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-rw-r--r--networking/arping.c401
1 files changed, 401 insertions, 0 deletions
diff --git a/networking/arping.c b/networking/arping.c
new file mode 100644
index 0000000..021dc86
--- /dev/null
+++ b/networking/arping.c
@@ -0,0 +1,401 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * arping.c - Ping hosts by ARP requests/replies
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ *
+ * Author: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
+ * Busybox port: Nick Fedchik <nick@fedchik.org.ua>
+ */
+
+#include <arpa/inet.h>
+#include <net/if.h>
+#include <netinet/ether.h>
+#include <netpacket/packet.h>
+
+#include "libbb.h"
+
+/* We don't expect to see 1000+ seconds delay, unsigned is enough */
+#define MONOTONIC_US() ((unsigned)monotonic_us())
+
+enum {
+ DAD = 1,
+ UNSOLICITED = 2,
+ ADVERT = 4,
+ QUIET = 8,
+ QUIT_ON_REPLY = 16,
+ BCAST_ONLY = 32,
+ UNICASTING = 64
+};
+
+struct globals {
+ struct in_addr src;
+ struct in_addr dst;
+ struct sockaddr_ll me;
+ struct sockaddr_ll he;
+ int sock_fd;
+
+ int count; // = -1;
+ unsigned last;
+ unsigned timeout_us;
+ unsigned start;
+
+ unsigned sent;
+ unsigned brd_sent;
+ unsigned received;
+ unsigned brd_recv;
+ unsigned req_recv;
+};
+#define G (*(struct globals*)&bb_common_bufsiz1)
+#define src (G.src )
+#define dst (G.dst )
+#define me (G.me )
+#define he (G.he )
+#define sock_fd (G.sock_fd )
+#define count (G.count )
+#define last (G.last )
+#define timeout_us (G.timeout_us)
+#define start (G.start )
+#define sent (G.sent )
+#define brd_sent (G.brd_sent )
+#define received (G.received )
+#define brd_recv (G.brd_recv )
+#define req_recv (G.req_recv )
+#define INIT_G() do { \
+ count = -1; \
+} while (0)
+
+// If GNUisms are not available...
+//static void *mempcpy(void *_dst, const void *_src, int n)
+//{
+// memcpy(_dst, _src, n);
+// return (char*)_dst + n;
+//}
+
+static int send_pack(struct in_addr *src_addr,
+ struct in_addr *dst_addr, struct sockaddr_ll *ME,
+ struct sockaddr_ll *HE)
+{
+ int err;
+ unsigned char buf[256];
+ struct arphdr *ah = (struct arphdr *) buf;
+ unsigned char *p = (unsigned char *) (ah + 1);
+
+ ah->ar_hrd = htons(ARPHRD_ETHER);
+ ah->ar_pro = htons(ETH_P_IP);
+ ah->ar_hln = ME->sll_halen;
+ ah->ar_pln = 4;
+ ah->ar_op = option_mask32 & ADVERT ? htons(ARPOP_REPLY) : htons(ARPOP_REQUEST);
+
+ p = mempcpy(p, &ME->sll_addr, ah->ar_hln);
+ p = mempcpy(p, src_addr, 4);
+
+ if (option_mask32 & ADVERT)
+ p = mempcpy(p, &ME->sll_addr, ah->ar_hln);
+ else
+ p = mempcpy(p, &HE->sll_addr, ah->ar_hln);
+
+ p = mempcpy(p, dst_addr, 4);
+
+ err = sendto(sock_fd, buf, p - buf, 0, (struct sockaddr *) HE, sizeof(*HE));
+ if (err == p - buf) {
+ last = MONOTONIC_US();
+ sent++;
+ if (!(option_mask32 & UNICASTING))
+ brd_sent++;
+ }
+ return err;
+}
+
+static void finish(void) NORETURN;
+static void finish(void)
+{
+ if (!(option_mask32 & QUIET)) {
+ printf("Sent %u probe(s) (%u broadcast(s))\n"
+ "Received %u repl%s"
+ " (%u request(s), %u broadcast(s))\n",
+ sent, brd_sent,
+ received, (received == 1) ? "ies" : "y",
+ req_recv, brd_recv);
+ }
+ if (option_mask32 & DAD)
+ exit(!!received);
+ if (option_mask32 & UNSOLICITED)
+ exit(EXIT_SUCCESS);
+ exit(!received);
+}
+
+static void catcher(void)
+{
+ unsigned now;
+
+ now = MONOTONIC_US();
+ if (start == 0)
+ start = now;
+
+ if (count == 0 || (timeout_us && (now - start) > timeout_us))
+ finish();
+
+ /* count < 0 means "infinite count" */
+ if (count > 0)
+ count--;
+
+ if (last == 0 || (now - last) > 500000) {
+ send_pack(&src, &dst, &me, &he);
+ if (count == 0 && (option_mask32 & UNSOLICITED))
+ finish();
+ }
+ alarm(1);
+}
+
+static bool recv_pack(unsigned char *buf, int len, struct sockaddr_ll *FROM)
+{
+ struct arphdr *ah = (struct arphdr *) buf;
+ unsigned char *p = (unsigned char *) (ah + 1);
+ struct in_addr src_ip, dst_ip;
+
+ /* Filter out wild packets */
+ if (FROM->sll_pkttype != PACKET_HOST
+ && FROM->sll_pkttype != PACKET_BROADCAST
+ && FROM->sll_pkttype != PACKET_MULTICAST)
+ return false;
+
+ /* Only these types are recognised */
+ if (ah->ar_op != htons(ARPOP_REQUEST) && ah->ar_op != htons(ARPOP_REPLY))
+ return false;
+
+ /* ARPHRD check and this darned FDDI hack here :-( */
+ if (ah->ar_hrd != htons(FROM->sll_hatype)
+ && (FROM->sll_hatype != ARPHRD_FDDI || ah->ar_hrd != htons(ARPHRD_ETHER)))
+ return false;
+
+ /* Protocol must be IP. */
+ if (ah->ar_pro != htons(ETH_P_IP)
+ || (ah->ar_pln != 4)
+ || (ah->ar_hln != me.sll_halen)
+ || (len < (int)(sizeof(*ah) + 2 * (4 + ah->ar_hln))))
+ return false;
+
+ memcpy(&src_ip, p + ah->ar_hln, 4);
+ memcpy(&dst_ip, p + ah->ar_hln + 4 + ah->ar_hln, 4);
+
+ if (dst.s_addr != src_ip.s_addr)
+ return false;
+ if (!(option_mask32 & DAD)) {
+ if ((src.s_addr != dst_ip.s_addr)
+ || (memcmp(p + ah->ar_hln + 4, &me.sll_addr, ah->ar_hln)))
+ return false;
+ } else {
+ /* DAD packet was:
+ src_ip = 0 (or some src)
+ src_hw = ME
+ dst_ip = tested address
+ dst_hw = <unspec>
+
+ We fail, if receive request/reply with:
+ src_ip = tested_address
+ src_hw != ME
+ if src_ip in request was not zero, check
+ also that it matches to dst_ip, otherwise
+ dst_ip/dst_hw do not matter.
+ */
+ if ((memcmp(p, &me.sll_addr, me.sll_halen) == 0)
+ || (src.s_addr && src.s_addr != dst_ip.s_addr))
+ return false;
+ }
+ if (!(option_mask32 & QUIET)) {
+ int s_printed = 0;
+
+ printf("%scast re%s from %s [%s]",
+ FROM->sll_pkttype == PACKET_HOST ? "Uni" : "Broad",
+ ah->ar_op == htons(ARPOP_REPLY) ? "ply" : "quest",
+ inet_ntoa(src_ip),
+ ether_ntoa((struct ether_addr *) p));
+ if (dst_ip.s_addr != src.s_addr) {
+ printf("for %s ", inet_ntoa(dst_ip));
+ s_printed = 1;
+ }
+ if (memcmp(p + ah->ar_hln + 4, me.sll_addr, ah->ar_hln)) {
+ if (!s_printed)
+ printf("for ");
+ printf("[%s]",
+ ether_ntoa((struct ether_addr *) p + ah->ar_hln + 4));
+ }
+
+ if (last) {
+ unsigned diff = MONOTONIC_US() - last;
+ printf(" %u.%03ums\n", diff / 1000, diff % 1000);
+ } else {
+ printf(" UNSOLICITED?\n");
+ }
+ fflush(stdout);
+ }
+ received++;
+ if (FROM->sll_pkttype != PACKET_HOST)
+ brd_recv++;
+ if (ah->ar_op == htons(ARPOP_REQUEST))
+ req_recv++;
+ if (option_mask32 & QUIT_ON_REPLY)
+ finish();
+ if (!(option_mask32 & BCAST_ONLY)) {
+ memcpy(he.sll_addr, p, me.sll_halen);
+ option_mask32 |= UNICASTING;
+ }
+ return true;
+}
+
+int arping_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int arping_main(int argc UNUSED_PARAM, char **argv)
+{
+ const char *device = "eth0";
+ char *source = NULL;
+ char *target;
+ unsigned char *packet;
+ char *err_str;
+
+ INIT_G();
+
+ sock_fd = xsocket(AF_PACKET, SOCK_DGRAM, 0);
+
+ // Drop suid root privileges
+ // Need to remove SUID_NEVER from applets.h for this to work
+ //xsetuid(getuid());
+
+ err_str = xasprintf("interface %s %%s", device);
+ {
+ unsigned opt;
+ char *str_timeout;
+
+ /* Dad also sets quit_on_reply.
+ * Advert also sets unsolicited.
+ */
+ opt_complementary = "=1:Df:AU:c+";
+ opt = getopt32(argv, "DUAqfbc:w:I:s:",
+ &count, &str_timeout, &device, &source);
+ if (opt & 0x80) /* -w: timeout */
+ timeout_us = xatou_range(str_timeout, 0, INT_MAX/2000000) * 1000000 + 500000;
+ //if (opt & 0x200) /* -s: source */
+ option_mask32 &= 0x3f; /* set respective flags */
+ }
+
+ target = argv[optind];
+
+ xfunc_error_retval = 2;
+
+ {
+ struct ifreq ifr;
+
+ memset(&ifr, 0, sizeof(ifr));
+ strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name) - 1);
+ /* We use ifr.ifr_name in error msg so that problem
+ * with truncated name will be visible */
+ ioctl_or_perror_and_die(sock_fd, SIOCGIFINDEX, &ifr, err_str, "not found");
+ me.sll_ifindex = ifr.ifr_ifindex;
+
+ xioctl(sock_fd, SIOCGIFFLAGS, (char *) &ifr);
+
+ if (!(ifr.ifr_flags & IFF_UP)) {
+ bb_error_msg_and_die(err_str, "is down");
+ }
+ if (ifr.ifr_flags & (IFF_NOARP | IFF_LOOPBACK)) {
+ bb_error_msg(err_str, "is not ARPable");
+ return (option_mask32 & DAD ? 0 : 2);
+ }
+ }
+
+ /* if (!inet_aton(target, &dst)) - not needed */ {
+ len_and_sockaddr *lsa;
+ lsa = xhost_and_af2sockaddr(target, 0, AF_INET);
+ memcpy(&dst, &lsa->u.sin.sin_addr.s_addr, 4);
+ if (ENABLE_FEATURE_CLEAN_UP)
+ free(lsa);
+ }
+
+ if (source && !inet_aton(source, &src)) {
+ bb_error_msg_and_die("invalid source address %s", source);
+ }
+
+ if ((option_mask32 & (DAD|UNSOLICITED)) == UNSOLICITED && src.s_addr == 0)
+ src = dst;
+
+ if (!(option_mask32 & DAD) || src.s_addr) {
+ struct sockaddr_in saddr;
+ int probe_fd = xsocket(AF_INET, SOCK_DGRAM, 0);
+
+ setsockopt_bindtodevice(probe_fd, device);
+ memset(&saddr, 0, sizeof(saddr));
+ saddr.sin_family = AF_INET;
+ if (src.s_addr) {
+ /* Check that this is indeed our IP */
+ saddr.sin_addr = src;
+ xbind(probe_fd, (struct sockaddr *) &saddr, sizeof(saddr));
+ } else { /* !(option_mask32 & DAD) case */
+ /* Find IP address on this iface */
+ socklen_t alen = sizeof(saddr);
+
+ saddr.sin_port = htons(1025);
+ saddr.sin_addr = dst;
+
+ if (setsockopt(probe_fd, SOL_SOCKET, SO_DONTROUTE, &const_int_1, sizeof(const_int_1)) == -1)
+ bb_perror_msg("setsockopt(SO_DONTROUTE)");
+ xconnect(probe_fd, (struct sockaddr *) &saddr, sizeof(saddr));
+ if (getsockname(probe_fd, (struct sockaddr *) &saddr, &alen) == -1) {
+ bb_perror_msg_and_die("getsockname");
+ }
+ if (saddr.sin_family != AF_INET)
+ bb_error_msg_and_die("no IP address configured");
+ src = saddr.sin_addr;
+ }
+ close(probe_fd);
+ }
+
+ me.sll_family = AF_PACKET;
+ //me.sll_ifindex = ifindex; - done before
+ me.sll_protocol = htons(ETH_P_ARP);
+ xbind(sock_fd, (struct sockaddr *) &me, sizeof(me));
+
+ {
+ socklen_t alen = sizeof(me);
+
+ if (getsockname(sock_fd, (struct sockaddr *) &me, &alen) == -1) {
+ bb_perror_msg_and_die("getsockname");
+ }
+ }
+ if (me.sll_halen == 0) {
+ bb_error_msg(err_str, "is not ARPable (no ll address)");
+ return (option_mask32 & DAD ? 0 : 2);
+ }
+ he = me;
+ memset(he.sll_addr, -1, he.sll_halen);
+
+ if (!(option_mask32 & QUIET)) {
+ /* inet_ntoa uses static storage, can't use in same printf */
+ printf("ARPING to %s", inet_ntoa(dst));
+ printf(" from %s via %s\n", inet_ntoa(src), device);
+ }
+
+ signal_SA_RESTART_empty_mask(SIGINT, (void (*)(int))finish);
+ signal_SA_RESTART_empty_mask(SIGALRM, (void (*)(int))catcher);
+
+ catcher();
+
+ packet = xmalloc(4096);
+ while (1) {
+ sigset_t sset, osset;
+ struct sockaddr_ll from;
+ socklen_t alen = sizeof(from);
+ int cc;
+
+ cc = recvfrom(sock_fd, packet, 4096, 0, (struct sockaddr *) &from, &alen);
+ if (cc < 0) {
+ bb_perror_msg("recvfrom");
+ continue;
+ }
+ sigemptyset(&sset);
+ sigaddset(&sset, SIGALRM);
+ sigaddset(&sset, SIGINT);
+ sigprocmask(SIG_BLOCK, &sset, &osset);
+ recv_pack(packet, cc, &from);
+ sigprocmask(SIG_SETMASK, &osset, NULL);
+ }
+}