Initial import from ToT git.

Bug: 9469682
Change-Id: I6fc32550557dc5e94e9ecbbb57b0ec30a844adb4
Upstream: git://git.linux-ipv6.org/gitroot/iputils.git
Commit: 608419a7804caf36a359875d2fdae0b3eb181387
diff --git a/ping_common.c b/ping_common.c
new file mode 100644
index 0000000..8d6b145
--- /dev/null
+++ b/ping_common.c
@@ -0,0 +1,1074 @@
+#include "ping_common.h"
+#include <ctype.h>
+#include <sched.h>
+#include <math.h>
+
+int options;
+
+int mark;
+int sndbuf;
+int ttl;
+int rtt;
+int rtt_addend;
+__u16 acked;
+
+struct rcvd_table rcvd_tbl;
+
+
+/* counters */
+long npackets;			/* max packets to transmit */
+long nreceived;			/* # of packets we got back */
+long nrepeats;			/* number of duplicates */
+long ntransmitted;		/* sequence # for outbound packets = #sent */
+long nchecksum;			/* replies with bad checksum */
+long nerrors;			/* icmp errors */
+int interval = 1000;		/* interval between packets (msec) */
+int preload;
+int deadline = 0;		/* time to die */
+int lingertime = MAXWAIT*1000;
+struct timeval start_time, cur_time;
+volatile int exiting;
+volatile int status_snapshot;
+int confirm = 0;
+volatile int in_pr_addr = 0;	/* pr_addr() is executing */
+jmp_buf pr_addr_jmp;
+
+/* Stupid workarounds for bugs/missing functionality in older linuces.
+ * confirm_flag fixes refusing service of kernels without MSG_CONFIRM.
+ * i.e. for linux-2.2 */
+int confirm_flag = MSG_CONFIRM;
+/* And this is workaround for bug in IP_RECVERR on raw sockets which is present
+ * in linux-2.2.[0-19], linux-2.4.[0-7] */
+int working_recverr;
+
+/* timing */
+int timing;			/* flag to do timing */
+long tmin = LONG_MAX;		/* minimum round trip time */
+long tmax;			/* maximum round trip time */
+/* Message for rpm maintainers: have _shame_. If you want
+ * to fix something send the patch to me for sanity checking.
+ * "sparcfix" patch is a complete non-sense, apparenly the person
+ * prepared it was stoned.
+ */
+long long tsum;			/* sum of all times, for doing average */
+long long tsum2;
+int  pipesize = -1;
+
+int datalen = DEFDATALEN;
+
+char *hostname;
+int uid;
+uid_t euid;
+int ident;			/* process id to identify our packets */
+
+static int screen_width = INT_MAX;
+
+#define ARRAY_SIZE(a)	(sizeof(a) / sizeof(a[0]))
+
+#ifdef CAPABILITIES
+static cap_value_t cap_raw = CAP_NET_RAW;
+static cap_value_t cap_admin = CAP_NET_ADMIN;
+#endif
+
+void limit_capabilities(void)
+{
+#ifdef CAPABILITIES
+	cap_t cap_cur_p;
+	cap_t cap_p;
+	cap_flag_value_t cap_ok;
+
+	cap_cur_p = cap_get_proc();
+	if (!cap_cur_p) {
+		perror("ping: cap_get_proc");
+		exit(-1);
+	}
+
+	cap_p = cap_init();
+	if (!cap_p) {
+		perror("ping: cap_init");
+		exit(-1);
+	}
+
+	cap_ok = CAP_CLEAR;
+	cap_get_flag(cap_cur_p, CAP_NET_ADMIN, CAP_PERMITTED, &cap_ok);
+
+	if (cap_ok != CAP_CLEAR)
+		cap_set_flag(cap_p, CAP_PERMITTED, 1, &cap_admin, CAP_SET);
+
+	cap_ok = CAP_CLEAR;
+	cap_get_flag(cap_cur_p, CAP_NET_RAW, CAP_PERMITTED, &cap_ok);
+
+	if (cap_ok != CAP_CLEAR)
+		cap_set_flag(cap_p, CAP_PERMITTED, 1, &cap_raw, CAP_SET);
+
+	if (cap_set_proc(cap_p) < 0) {
+		perror("ping: cap_set_proc");
+		exit(-1);
+	}
+
+	if (prctl(PR_SET_KEEPCAPS, 1) < 0) {
+		perror("ping: prctl");
+		exit(-1);
+	}
+
+	if (setuid(getuid()) < 0) {
+		perror("setuid");
+		exit(-1);
+	}
+
+	if (prctl(PR_SET_KEEPCAPS, 0) < 0) {
+		perror("ping: prctl");
+		exit(-1);
+	}
+
+	cap_free(cap_p);
+	cap_free(cap_cur_p);
+#endif
+	uid = getuid();
+	euid = geteuid();
+#ifndef CAPABILITIES
+	if (seteuid(uid)) {
+		perror("ping: setuid");
+		exit(-1);
+	}
+#endif
+}
+
+#ifdef CAPABILITIES
+int modify_capability(cap_value_t cap, cap_flag_value_t on)
+{
+	cap_t cap_p = cap_get_proc();
+	cap_flag_value_t cap_ok;
+	int rc = -1;
+
+	if (!cap_p) {
+		perror("ping: cap_get_proc");
+		goto out;
+	}
+
+	cap_ok = CAP_CLEAR;
+	cap_get_flag(cap_p, cap, CAP_PERMITTED, &cap_ok);
+	if (cap_ok == CAP_CLEAR) {
+		rc = on ? -1 : 0;
+		goto out;
+	}
+
+	cap_set_flag(cap_p, CAP_EFFECTIVE, 1, &cap, on);
+
+	if (cap_set_proc(cap_p) < 0) {
+		perror("ping: cap_set_proc");
+		goto out;
+	}
+
+	cap_free(cap_p);
+
+	rc = 0;
+out:
+	if (cap_p)
+		cap_free(cap_p);
+	return rc;
+}
+#else
+int modify_capability(int on)
+{
+	if (seteuid(on ? euid : getuid())) {
+		perror("seteuid");
+		return -1;
+	}
+
+	return 0;
+}
+#endif
+
+void drop_capabilities(void)
+{
+#ifdef CAPABILITIES
+	cap_t cap = cap_init();
+	if (cap_set_proc(cap) < 0) {
+		perror("ping: cap_set_proc");
+		exit(-1);
+	}
+	cap_free(cap);
+#else
+	if (setuid(getuid())) {
+		perror("ping: setuid");
+		exit(-1);
+	}
+#endif
+}
+
+/* Fills all the outpack, excluding ICMP header, but _including_
+ * timestamp area with supplied pattern.
+ */
+static void fill(char *patp)
+{
+	int ii, jj, kk;
+	int pat[16];
+	char *cp;
+	u_char *bp = outpack+8;
+
+#ifdef USE_IDN
+	setlocale(LC_ALL, "C");
+#endif
+
+	for (cp = patp; *cp; cp++) {
+		if (!isxdigit(*cp)) {
+			fprintf(stderr,
+				"ping: patterns must be specified as hex digits.\n");
+			exit(2);
+		}
+	}
+	ii = sscanf(patp,
+	    "%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x",
+	    &pat[0], &pat[1], &pat[2], &pat[3], &pat[4], &pat[5], &pat[6],
+	    &pat[7], &pat[8], &pat[9], &pat[10], &pat[11], &pat[12],
+	    &pat[13], &pat[14], &pat[15]);
+
+	if (ii > 0) {
+		for (kk = 0; kk <= maxpacket - (8 + ii); kk += ii)
+			for (jj = 0; jj < ii; ++jj)
+				bp[jj + kk] = pat[jj];
+	}
+	if (!(options & F_QUIET)) {
+		printf("PATTERN: 0x");
+		for (jj = 0; jj < ii; ++jj)
+			printf("%02x", bp[jj] & 0xFF);
+		printf("\n");
+	}
+
+#ifdef USE_IDN
+	setlocale(LC_ALL, "");
+#endif
+}
+
+void common_options(int ch)
+{
+	switch(ch) {
+	case 'a':
+		options |= F_AUDIBLE;
+		break;
+	case 'A':
+		options |= F_ADAPTIVE;
+		break;
+	case 'c':
+		npackets = atoi(optarg);
+		if (npackets <= 0) {
+			fprintf(stderr, "ping: bad number of packets to transmit.\n");
+			exit(2);
+		}
+		break;
+	case 'd':
+		options |= F_SO_DEBUG;
+		break;
+	case 'D':
+		options |= F_PTIMEOFDAY;
+		break;
+	case 'i':		/* wait between sending packets */
+	{
+		double dbl;
+		char *ep;
+
+		errno = 0;
+		dbl = strtod(optarg, &ep);
+
+		if (errno || *ep != '\0' ||
+		    !finite(dbl) || dbl < 0.0 || dbl >= (double)INT_MAX / 1000 - 1.0) {
+			fprintf(stderr, "ping: bad timing interval\n");
+			exit(2);
+		}
+
+		interval = (int)(dbl * 1000);
+
+		options |= F_INTERVAL;
+		break;
+	}
+	case 'm':
+	{
+		char *endp;
+		mark = (int)strtoul(optarg, &endp, 10);
+		if (mark < 0 || *endp != '\0') {
+			fprintf(stderr, "mark cannot be negative\n");
+			exit(2);
+		}
+		options |= F_MARK;
+		break;
+	}
+	case 'w':
+		deadline = atoi(optarg);
+		if (deadline < 0) {
+			fprintf(stderr, "ping: bad wait time.\n");
+			exit(2);
+		}
+		break;
+	case 'l':
+		preload = atoi(optarg);
+		if (preload <= 0) {
+			fprintf(stderr, "ping: bad preload value, should be 1..%d\n", MAX_DUP_CHK);
+			exit(2);
+		}
+		if (preload > MAX_DUP_CHK)
+			preload = MAX_DUP_CHK;
+		if (uid && preload > 3) {
+			fprintf(stderr, "ping: cannot set preload to value > 3\n");
+			exit(2);
+		}
+		break;
+	case 'O':
+		options |= F_OUTSTANDING;
+		break;
+	case 'S':
+		sndbuf = atoi(optarg);
+		if (sndbuf <= 0) {
+			fprintf(stderr, "ping: bad sndbuf value.\n");
+			exit(2);
+		}
+		break;
+	case 'f':
+		options |= F_FLOOD;
+		setbuf(stdout, (char *)NULL);
+		/* fallthrough to numeric - avoid gethostbyaddr during flood */
+	case 'n':
+		options |= F_NUMERIC;
+		break;
+	case 'p':		/* fill buffer with user pattern */
+		options |= F_PINGFILLED;
+		fill(optarg);
+		break;
+	case 'q':
+		options |= F_QUIET;
+		break;
+	case 'r':
+		options |= F_SO_DONTROUTE;
+		break;
+	case 's':		/* size of packet to send */
+		datalen = atoi(optarg);
+		if (datalen < 0) {
+			fprintf(stderr, "ping: illegal negative packet size %d.\n", datalen);
+			exit(2);
+		}
+		if (datalen > maxpacket - 8) {
+			fprintf(stderr, "ping: packet size too large: %d\n",
+				datalen);
+			exit(2);
+		}
+		break;
+	case 'v':
+		options |= F_VERBOSE;
+		break;
+	case 'L':
+		options |= F_NOLOOP;
+		break;
+	case 't':
+		options |= F_TTL;
+		ttl = atoi(optarg);
+		if (ttl < 0 || ttl > 255) {
+			fprintf(stderr, "ping: ttl %u out of range\n", ttl);
+			exit(2);
+		}
+		break;
+	case 'U':
+		options |= F_LATENCY;
+		break;
+	case 'B':
+		options |= F_STRICTSOURCE;
+		break;
+	case 'W':
+		lingertime = atoi(optarg);
+		if (lingertime < 0 || lingertime > INT_MAX/1000000) {
+			fprintf(stderr, "ping: bad linger time.\n");
+			exit(2);
+		}
+		lingertime *= 1000;
+		break;
+	case 'V':
+		printf("ping utility, iputils-%s\n", SNAPSHOT);
+		exit(0);
+	default:
+		abort();
+	}
+}
+
+
+static void sigexit(int signo)
+{
+	exiting = 1;
+	if (in_pr_addr)
+		longjmp(pr_addr_jmp, 0);
+}
+
+static void sigstatus(int signo)
+{
+	status_snapshot = 1;
+}
+
+
+int __schedule_exit(int next)
+{
+	static unsigned long waittime;
+	struct itimerval it;
+
+	if (waittime)
+		return next;
+
+	if (nreceived) {
+		waittime = 2 * tmax;
+		if (waittime < 1000*interval)
+			waittime = 1000*interval;
+	} else
+		waittime = lingertime*1000;
+
+	if (next < 0 || next < waittime/1000)
+		next = waittime/1000;
+
+	it.it_interval.tv_sec = 0;
+	it.it_interval.tv_usec = 0;
+	it.it_value.tv_sec = waittime/1000000;
+	it.it_value.tv_usec = waittime%1000000;
+	setitimer(ITIMER_REAL, &it, NULL);
+	return next;
+}
+
+static inline void update_interval(void)
+{
+	int est = rtt ? rtt/8 : interval*1000;
+
+	interval = (est+rtt_addend+500)/1000;
+	if (uid && interval < MINUSERINTERVAL)
+		interval = MINUSERINTERVAL;
+}
+
+/*
+ * Print timestamp
+ */
+void print_timestamp(void)
+{
+	if (options & F_PTIMEOFDAY) {
+		struct timeval tv;
+		gettimeofday(&tv, NULL);
+		printf("[%lu.%06lu] ",
+		       (unsigned long)tv.tv_sec, (unsigned long)tv.tv_usec);
+	}
+}
+
+/*
+ * pinger --
+ * 	Compose and transmit an ICMP ECHO REQUEST packet.  The IP packet
+ * will be added on by the kernel.  The ID field is our UNIX process ID,
+ * and the sequence number is an ascending integer.  The first 8 bytes
+ * of the data portion are used to hold a UNIX "timeval" struct in VAX
+ * byte-order, to compute the round-trip time.
+ */
+int pinger(void)
+{
+	static int oom_count;
+	static int tokens;
+	int i;
+
+	/* Have we already sent enough? If we have, return an arbitrary positive value. */
+	if (exiting || (npackets && ntransmitted >= npackets && !deadline))
+		return 1000;
+
+	/* Check that packets < rate*time + preload */
+	if (cur_time.tv_sec == 0) {
+		gettimeofday(&cur_time, NULL);
+		tokens = interval*(preload-1);
+	} else {
+		long ntokens;
+		struct timeval tv;
+
+		gettimeofday(&tv, NULL);
+		ntokens = (tv.tv_sec - cur_time.tv_sec)*1000 +
+			(tv.tv_usec-cur_time.tv_usec)/1000;
+		if (!interval) {
+			/* Case of unlimited flood is special;
+			 * if we see no reply, they are limited to 100pps */
+			if (ntokens < MININTERVAL && in_flight() >= preload)
+				return MININTERVAL-ntokens;
+		}
+		ntokens += tokens;
+		if (ntokens > interval*preload)
+			ntokens = interval*preload;
+		if (ntokens < interval)
+			return interval - ntokens;
+
+		cur_time = tv;
+		tokens = ntokens - interval;
+	}
+
+	if (options & F_OUTSTANDING) {
+		if (ntransmitted > 0 && !rcvd_test(ntransmitted)) {
+			print_timestamp();
+			printf("no answer yet for icmp_seq=%lu\n", (ntransmitted % MAX_DUP_CHK));
+			fflush(stdout);
+		}
+	}
+
+resend:
+	i = send_probe();
+
+	if (i == 0) {
+		oom_count = 0;
+		advance_ntransmitted();
+		if (!(options & F_QUIET) && (options & F_FLOOD)) {
+			/* Very silly, but without this output with
+			 * high preload or pipe size is very confusing. */
+			if ((preload < screen_width && pipesize < screen_width) ||
+			    in_flight() < screen_width)
+				write_stdout(".", 1);
+		}
+		return interval - tokens;
+	}
+
+	/* And handle various errors... */
+	if (i > 0) {
+		/* Apparently, it is some fatal bug. */
+		abort();
+	} else if (errno == ENOBUFS || errno == ENOMEM) {
+		int nores_interval;
+
+		/* Device queue overflow or OOM. Packet is not sent. */
+		tokens = 0;
+		/* Slowdown. This works only in adaptive mode (option -A) */
+		rtt_addend += (rtt < 8*50000 ? rtt/8 : 50000);
+		if (options&F_ADAPTIVE)
+			update_interval();
+		nores_interval = SCHINT(interval/2);
+		if (nores_interval > 500)
+			nores_interval = 500;
+		oom_count++;
+		if (oom_count*nores_interval < lingertime)
+			return nores_interval;
+		i = 0;
+		/* Fall to hard error. It is to avoid complete deadlock
+		 * on stuck output device even when dealine was not requested.
+		 * Expected timings are screwed up in any case, but we will
+		 * exit some day. :-) */
+	} else if (errno == EAGAIN) {
+		/* Socket buffer is full. */
+		tokens += interval;
+		return MININTERVAL;
+	} else {
+		if ((i=receive_error_msg()) > 0) {
+			/* An ICMP error arrived. */
+			tokens += interval;
+			return MININTERVAL;
+		}
+		/* Compatibility with old linuces. */
+		if (i == 0 && confirm_flag && errno == EINVAL) {
+			confirm_flag = 0;
+			errno = 0;
+		}
+		if (!errno)
+			goto resend;
+	}
+
+	/* Hard local error. Pretend we sent packet. */
+	advance_ntransmitted();
+
+	if (i == 0 && !(options & F_QUIET)) {
+		if (options & F_FLOOD)
+			write_stdout("E", 1);
+		else
+			perror("ping: sendmsg");
+	}
+	tokens = 0;
+	return SCHINT(interval);
+}
+
+/* Set socket buffers, "alloc" is an estimate of memory taken by single packet. */
+
+void sock_setbufs(int icmp_sock, int alloc)
+{
+	int rcvbuf, hold;
+	socklen_t tmplen = sizeof(hold);
+
+	if (!sndbuf)
+		sndbuf = alloc;
+	setsockopt(icmp_sock, SOL_SOCKET, SO_SNDBUF, (char *)&sndbuf, sizeof(sndbuf));
+
+	rcvbuf = hold = alloc * preload;
+	if (hold < 65536)
+		hold = 65536;
+	setsockopt(icmp_sock, SOL_SOCKET, SO_RCVBUF, (char *)&hold, sizeof(hold));
+	if (getsockopt(icmp_sock, SOL_SOCKET, SO_RCVBUF, (char *)&hold, &tmplen) == 0) {
+		if (hold < rcvbuf)
+			fprintf(stderr, "WARNING: probably, rcvbuf is not enough to hold preload.\n");
+	}
+}
+
+/* Protocol independent setup and parameter checks. */
+
+void setup(int icmp_sock)
+{
+	int hold;
+	struct timeval tv;
+	sigset_t sset;
+
+	if ((options & F_FLOOD) && !(options & F_INTERVAL))
+		interval = 0;
+
+	if (uid && interval < MINUSERINTERVAL) {
+		fprintf(stderr, "ping: cannot flood; minimal interval, allowed for user, is %dms\n", MINUSERINTERVAL);
+		exit(2);
+	}
+
+	if (interval >= INT_MAX/preload) {
+		fprintf(stderr, "ping: illegal preload and/or interval\n");
+		exit(2);
+	}
+
+	hold = 1;
+	if (options & F_SO_DEBUG)
+		setsockopt(icmp_sock, SOL_SOCKET, SO_DEBUG, (char *)&hold, sizeof(hold));
+	if (options & F_SO_DONTROUTE)
+		setsockopt(icmp_sock, SOL_SOCKET, SO_DONTROUTE, (char *)&hold, sizeof(hold));
+
+#ifdef SO_TIMESTAMP
+	if (!(options&F_LATENCY)) {
+		int on = 1;
+		if (setsockopt(icmp_sock, SOL_SOCKET, SO_TIMESTAMP, &on, sizeof(on)))
+			fprintf(stderr, "Warning: no SO_TIMESTAMP support, falling back to SIOCGSTAMP\n");
+	}
+#endif
+#ifdef SO_MARK
+	if (options & F_MARK) {
+		int ret;
+
+		enable_capability_admin();
+		ret = setsockopt(icmp_sock, SOL_SOCKET, SO_MARK, &mark, sizeof(mark));
+		disable_capability_admin();
+
+		if (ret == -1) {
+			/* we probably dont wanna exit since old kernels
+			 * dont support mark ..
+			*/
+			fprintf(stderr, "Warning: Failed to set mark %d\n", mark);
+		}
+	}
+#endif
+
+	/* Set some SNDTIMEO to prevent blocking forever
+	 * on sends, when device is too slow or stalls. Just put limit
+	 * of one second, or "interval", if it is less.
+	 */
+	tv.tv_sec = 1;
+	tv.tv_usec = 0;
+	if (interval < 1000) {
+		tv.tv_sec = 0;
+		tv.tv_usec = 1000 * SCHINT(interval);
+	}
+	setsockopt(icmp_sock, SOL_SOCKET, SO_SNDTIMEO, (char*)&tv, sizeof(tv));
+
+	/* Set RCVTIMEO to "interval". Note, it is just an optimization
+	 * allowing to avoid redundant poll(). */
+	tv.tv_sec = SCHINT(interval)/1000;
+	tv.tv_usec = 1000*(SCHINT(interval)%1000);
+	if (setsockopt(icmp_sock, SOL_SOCKET, SO_RCVTIMEO, (char*)&tv, sizeof(tv)))
+		options |= F_FLOOD_POLL;
+
+	if (!(options & F_PINGFILLED)) {
+		int i;
+		u_char *p = outpack+8;
+
+		/* Do not forget about case of small datalen,
+		 * fill timestamp area too!
+		 */
+		for (i = 0; i < datalen; ++i)
+			*p++ = i;
+	}
+
+	ident = htons(getpid() & 0xFFFF);
+
+	set_signal(SIGINT, sigexit);
+	set_signal(SIGALRM, sigexit);
+	set_signal(SIGQUIT, sigstatus);
+
+	sigemptyset(&sset);
+	sigprocmask(SIG_SETMASK, &sset, NULL);
+
+	gettimeofday(&start_time, NULL);
+
+	if (deadline) {
+		struct itimerval it;
+
+		it.it_interval.tv_sec = 0;
+		it.it_interval.tv_usec = 0;
+		it.it_value.tv_sec = deadline;
+		it.it_value.tv_usec = 0;
+		setitimer(ITIMER_REAL, &it, NULL);
+	}
+
+	if (isatty(STDOUT_FILENO)) {
+		struct winsize w;
+
+		if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &w) != -1) {
+			if (w.ws_col > 0)
+				screen_width = w.ws_col;
+		}
+	}
+}
+
+void main_loop(int icmp_sock, __u8 *packet, int packlen)
+{
+	char addrbuf[128];
+	char ans_data[4096];
+	struct iovec iov;
+	struct msghdr msg;
+	struct cmsghdr *c;
+	int cc;
+	int next;
+	int polling;
+
+	iov.iov_base = (char *)packet;
+
+	for (;;) {
+		/* Check exit conditions. */
+		if (exiting)
+			break;
+		if (npackets && nreceived + nerrors >= npackets)
+			break;
+		if (deadline && nerrors)
+			break;
+		/* Check for and do special actions. */
+		if (status_snapshot)
+			status();
+
+		/* Send probes scheduled to this time. */
+		do {
+			next = pinger();
+			next = schedule_exit(next);
+		} while (next <= 0);
+
+		/* "next" is time to send next probe, if positive.
+		 * If next<=0 send now or as soon as possible. */
+
+		/* Technical part. Looks wicked. Could be dropped,
+		 * if everyone used the newest kernel. :-)
+		 * Its purpose is:
+		 * 1. Provide intervals less than resolution of scheduler.
+		 *    Solution: spinning.
+		 * 2. Avoid use of poll(), when recvmsg() can provide
+		 *    timed waiting (SO_RCVTIMEO). */
+		polling = 0;
+		if ((options & (F_ADAPTIVE|F_FLOOD_POLL)) || next<SCHINT(interval)) {
+			int recv_expected = in_flight();
+
+			/* If we are here, recvmsg() is unable to wait for
+			 * required timeout. */
+			if (1000 % HZ == 0 ? next <= 1000 / HZ : (next < INT_MAX / HZ && next * HZ <= 1000)) {
+				/* Very short timeout... So, if we wait for
+				 * something, we sleep for MININTERVAL.
+				 * Otherwise, spin! */
+				if (recv_expected) {
+					next = MININTERVAL;
+				} else {
+					next = 0;
+					/* When spinning, no reasons to poll.
+					 * Use nonblocking recvmsg() instead. */
+					polling = MSG_DONTWAIT;
+					/* But yield yet. */
+					sched_yield();
+				}
+			}
+
+			if (!polling &&
+			    ((options & (F_ADAPTIVE|F_FLOOD_POLL)) || interval)) {
+				struct pollfd pset;
+				pset.fd = icmp_sock;
+				pset.events = POLLIN|POLLERR;
+				pset.revents = 0;
+				if (poll(&pset, 1, next) < 1 ||
+				    !(pset.revents&(POLLIN|POLLERR)))
+					continue;
+				polling = MSG_DONTWAIT;
+			}
+		}
+
+		for (;;) {
+			struct timeval *recv_timep = NULL;
+			struct timeval recv_time;
+			int not_ours = 0; /* Raw socket can receive messages
+					   * destined to other running pings. */
+
+			iov.iov_len = packlen;
+			memset(&msg, 0, sizeof(msg));
+			msg.msg_name = addrbuf;
+			msg.msg_namelen = sizeof(addrbuf);
+			msg.msg_iov = &iov;
+			msg.msg_iovlen = 1;
+			msg.msg_control = ans_data;
+			msg.msg_controllen = sizeof(ans_data);
+
+			cc = recvmsg(icmp_sock, &msg, polling);
+			polling = MSG_DONTWAIT;
+
+			if (cc < 0) {
+				if (errno == EAGAIN || errno == EINTR)
+					break;
+				if (!receive_error_msg()) {
+					if (errno) {
+						perror("ping: recvmsg");
+						break;
+					}
+					not_ours = 1;
+				}
+			} else {
+
+#ifdef SO_TIMESTAMP
+				for (c = CMSG_FIRSTHDR(&msg); c; c = CMSG_NXTHDR(&msg, c)) {
+					if (c->cmsg_level != SOL_SOCKET ||
+					    c->cmsg_type != SO_TIMESTAMP)
+						continue;
+					if (c->cmsg_len < CMSG_LEN(sizeof(struct timeval)))
+						continue;
+					recv_timep = (struct timeval*)CMSG_DATA(c);
+				}
+#endif
+
+				if ((options&F_LATENCY) || recv_timep == NULL) {
+					if ((options&F_LATENCY) ||
+					    ioctl(icmp_sock, SIOCGSTAMP, &recv_time))
+						gettimeofday(&recv_time, NULL);
+					recv_timep = &recv_time;
+				}
+
+				not_ours = parse_reply(&msg, cc, addrbuf, recv_timep);
+			}
+
+			/* See? ... someone runs another ping on this host. */
+			if (not_ours)
+				install_filter();
+
+			/* If nothing is in flight, "break" returns us to pinger. */
+			if (in_flight() == 0)
+				break;
+
+			/* Otherwise, try to recvmsg() again. recvmsg()
+			 * is nonblocking after the first iteration, so that
+			 * if nothing is queued, it will receive EAGAIN
+			 * and return to pinger. */
+		}
+	}
+	finish();
+}
+
+int gather_statistics(__u8 *icmph, int icmplen,
+		      int cc, __u16 seq, int hops,
+		      int csfailed, struct timeval *tv, char *from,
+		      void (*pr_reply)(__u8 *icmph, int cc))
+{
+	int dupflag = 0;
+	long triptime = 0;
+	__u8 *ptr = icmph + icmplen;
+
+	++nreceived;
+	if (!csfailed)
+		acknowledge(seq);
+
+	if (timing && cc >= 8+sizeof(struct timeval)) {
+		struct timeval tmp_tv;
+		memcpy(&tmp_tv, ptr, sizeof(tmp_tv));
+
+restamp:
+		tvsub(tv, &tmp_tv);
+		triptime = tv->tv_sec * 1000000 + tv->tv_usec;
+		if (triptime < 0) {
+			fprintf(stderr, "Warning: time of day goes back (%ldus), taking countermeasures.\n", triptime);
+			triptime = 0;
+			if (!(options & F_LATENCY)) {
+				gettimeofday(tv, NULL);
+				options |= F_LATENCY;
+				goto restamp;
+			}
+		}
+		if (!csfailed) {
+			tsum += triptime;
+			tsum2 += (long long)triptime * (long long)triptime;
+			if (triptime < tmin)
+				tmin = triptime;
+			if (triptime > tmax)
+				tmax = triptime;
+			if (!rtt)
+				rtt = triptime*8;
+			else
+				rtt += triptime-rtt/8;
+			if (options&F_ADAPTIVE)
+				update_interval();
+		}
+	}
+
+	if (csfailed) {
+		++nchecksum;
+		--nreceived;
+	} else if (rcvd_test(seq)) {
+		++nrepeats;
+		--nreceived;
+		dupflag = 1;
+	} else {
+		rcvd_set(seq);
+		dupflag = 0;
+	}
+	confirm = confirm_flag;
+
+	if (options & F_QUIET)
+		return 1;
+
+	if (options & F_FLOOD) {
+		if (!csfailed)
+			write_stdout("\b \b", 3);
+		else
+			write_stdout("\bC", 2);
+	} else {
+		int i;
+		__u8 *cp, *dp;
+
+		print_timestamp();
+		printf("%d bytes from %s:", cc, from);
+
+		if (pr_reply)
+			pr_reply(icmph, cc);
+
+		if (hops >= 0)
+			printf(" ttl=%d", hops);
+
+		if (cc < datalen+8) {
+			printf(" (truncated)\n");
+			return 1;
+		}
+		if (timing) {
+			if (triptime >= 100000)
+				printf(" time=%ld ms", triptime/1000);
+			else if (triptime >= 10000)
+				printf(" time=%ld.%01ld ms", triptime/1000,
+				       (triptime%1000)/100);
+			else if (triptime >= 1000)
+				printf(" time=%ld.%02ld ms", triptime/1000,
+				       (triptime%1000)/10);
+			else
+				printf(" time=%ld.%03ld ms", triptime/1000,
+				       triptime%1000);
+		}
+		if (dupflag)
+			printf(" (DUP!)");
+		if (csfailed)
+			printf(" (BAD CHECKSUM!)");
+
+		/* check the data */
+		cp = ((u_char*)ptr) + sizeof(struct timeval);
+		dp = &outpack[8 + sizeof(struct timeval)];
+		for (i = sizeof(struct timeval); i < datalen; ++i, ++cp, ++dp) {
+			if (*cp != *dp) {
+				printf("\nwrong data byte #%d should be 0x%x but was 0x%x",
+				       i, *dp, *cp);
+				cp = (u_char*)ptr + sizeof(struct timeval);
+				for (i = sizeof(struct timeval); i < datalen; ++i, ++cp) {
+					if ((i % 32) == sizeof(struct timeval))
+						printf("\n#%d\t", i);
+					printf("%x ", *cp);
+				}
+				break;
+			}
+		}
+	}
+	return 0;
+}
+
+static long llsqrt(long long a)
+{
+	long long prev = ~((long long)1 << 63);
+	long long x = a;
+
+	if (x > 0) {
+		while (x < prev) {
+			prev = x;
+			x = (x+(a/x))/2;
+		}
+	}
+
+	return (long)x;
+}
+
+/*
+ * finish --
+ *	Print out statistics, and give up.
+ */
+void finish(void)
+{
+	struct timeval tv = cur_time;
+	char *comma = "";
+
+	tvsub(&tv, &start_time);
+
+	putchar('\n');
+	fflush(stdout);
+	printf("--- %s ping statistics ---\n", hostname);
+	printf("%ld packets transmitted, ", ntransmitted);
+	printf("%ld received", nreceived);
+	if (nrepeats)
+		printf(", +%ld duplicates", nrepeats);
+	if (nchecksum)
+		printf(", +%ld corrupted", nchecksum);
+	if (nerrors)
+		printf(", +%ld errors", nerrors);
+	if (ntransmitted) {
+		printf(", %d%% packet loss",
+		       (int) ((((long long)(ntransmitted - nreceived)) * 100) /
+			      ntransmitted));
+		printf(", time %ldms", 1000*tv.tv_sec+tv.tv_usec/1000);
+	}
+	putchar('\n');
+
+	if (nreceived && timing) {
+		long tmdev;
+
+		tsum /= nreceived + nrepeats;
+		tsum2 /= nreceived + nrepeats;
+		tmdev = llsqrt(tsum2 - tsum * tsum);
+
+		printf("rtt min/avg/max/mdev = %ld.%03ld/%lu.%03ld/%ld.%03ld/%ld.%03ld ms",
+		       (long)tmin/1000, (long)tmin%1000,
+		       (unsigned long)(tsum/1000), (long)(tsum%1000),
+		       (long)tmax/1000, (long)tmax%1000,
+		       (long)tmdev/1000, (long)tmdev%1000
+		       );
+		comma = ", ";
+	}
+	if (pipesize > 1) {
+		printf("%spipe %d", comma, pipesize);
+		comma = ", ";
+	}
+	if (nreceived && (!interval || (options&(F_FLOOD|F_ADAPTIVE))) && ntransmitted > 1) {
+		int ipg = (1000000*(long long)tv.tv_sec+tv.tv_usec)/(ntransmitted-1);
+		printf("%sipg/ewma %d.%03d/%d.%03d ms",
+		       comma, ipg/1000, ipg%1000, rtt/8000, (rtt/8)%1000);
+	}
+	putchar('\n');
+	exit(!nreceived || (deadline && nreceived < npackets));
+}
+
+
+void status(void)
+{
+	int loss = 0;
+	long tavg = 0;
+
+	status_snapshot = 0;
+
+	if (ntransmitted)
+		loss = (((long long)(ntransmitted - nreceived)) * 100) / ntransmitted;
+
+	fprintf(stderr, "\r%ld/%ld packets, %d%% loss", ntransmitted, nreceived, loss);
+
+	if (nreceived && timing) {
+		tavg = tsum / (nreceived + nrepeats);
+
+		fprintf(stderr, ", min/avg/ewma/max = %ld.%03ld/%lu.%03ld/%d.%03d/%ld.%03ld ms",
+		       (long)tmin/1000, (long)tmin%1000,
+		       tavg/1000, tavg%1000,
+		       rtt/8000, (rtt/8)%1000,
+		       (long)tmax/1000, (long)tmax%1000
+		       );
+	}
+	fprintf(stderr, "\n");
+}
+