hush/networking/ping.c

429 lines
10 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Mini ping implementation for busybox
*
* Copyright (C) 1999 by Randolph Chung <tausq@debian.org>
*
* Adapted from the ping in netkit-base 0.10:
* Copyright (c) 1989 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Mike Muuss.
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
#include <netinet/ip_icmp.h>
#include "busybox.h"
enum {
DEFDATALEN = 56,
MAXIPLEN = 60,
MAXICMPLEN = 76,
MAXPACKET = 65468,
MAX_DUP_CHK = (8 * 128),
MAXWAIT = 10,
PINGINTERVAL = 1 /* second */
};
static void ping(const char *host);
/* common routines */
static int in_cksum(unsigned short *buf, int sz)
{
int nleft = sz;
int sum = 0;
unsigned short *w = buf;
unsigned short ans = 0;
while (nleft > 1) {
sum += *w++;
nleft -= 2;
}
if (nleft == 1) {
*(unsigned char *) (&ans) = *(unsigned char *) w;
sum += ans;
}
sum = (sum >> 16) + (sum & 0xFFFF);
sum += (sum >> 16);
ans = ~sum;
return ans;
}
#ifndef CONFIG_FEATURE_FANCY_PING
/* simple version */
static char *hostname;
static void noresp(int ign)
{
printf("No response from %s\n", hostname);
exit(EXIT_FAILURE);
}
static void ping(const char *host)
{
struct hostent *h;
struct sockaddr_in pingaddr;
struct icmp *pkt;
int pingsock, c;
char packet[DEFDATALEN + MAXIPLEN + MAXICMPLEN];
pingsock = create_icmp_socket();
memset(&pingaddr, 0, sizeof(pingaddr));
pingaddr.sin_family = AF_INET;
h = xgethostbyname(host);
memcpy(&pingaddr.sin_addr, h->h_addr, sizeof(pingaddr.sin_addr));
hostname = h->h_name;
pkt = (struct icmp *) packet;
memset(pkt, 0, sizeof(packet));
pkt->icmp_type = ICMP_ECHO;
pkt->icmp_cksum = in_cksum((unsigned short *) pkt, sizeof(packet));
c = sendto(pingsock, packet, DEFDATALEN + ICMP_MINLEN, 0,
(struct sockaddr *) &pingaddr, sizeof(struct sockaddr_in));
if (c < 0) {
if (ENABLE_FEATURE_CLEAN_UP) close(pingsock);
bb_perror_msg_and_die("sendto");
}
signal(SIGALRM, noresp);
alarm(5); /* give the host 5000ms to respond */
/* listen for replies */
while (1) {
struct sockaddr_in from;
socklen_t fromlen = sizeof(from);
c = recvfrom(pingsock, packet, sizeof(packet), 0,
(struct sockaddr *) &from, &fromlen);
if (c < 0) {
if (errno != EINTR)
bb_perror_msg("recvfrom");
continue;
}
if (c >= 76) { /* ip + icmp */
struct iphdr *iphdr = (struct iphdr *) packet;
pkt = (struct icmp *) (packet + (iphdr->ihl << 2)); /* skip ip hdr */
if (pkt->icmp_type == ICMP_ECHOREPLY)
break;
}
}
if (ENABLE_FEATURE_CLEAN_UP)
close(pingsock);
printf("%s is alive!\n", hostname);
}
int ping_main(int argc, char **argv)
{
argc--;
argv++;
if (argc < 1)
bb_show_usage();
ping(*argv);
return EXIT_SUCCESS;
}
#else /* ! CONFIG_FEATURE_FANCY_PING */
/* full(er) version */
#define OPT_STRING "qc:s:I:"
enum {
OPT_QUIET = 1 << 0,
};
static struct sockaddr_in pingaddr;
static struct sockaddr_in sourceaddr;
static int pingsock = -1;
static unsigned datalen; /* intentionally uninitialized to work around gcc bug */
static unsigned long ntransmitted, nreceived, nrepeats, pingcount;
static int myid;
static unsigned long tmin = ULONG_MAX, tmax, tsum;
static char rcvd_tbl[MAX_DUP_CHK / 8];
static struct hostent *hostent;
static void sendping(int);
static void pingstats(int);
static void unpack(char *, int, struct sockaddr_in *);
#define A(bit) rcvd_tbl[(bit)>>3] /* identify byte in array */
#define B(bit) (1 << ((bit) & 0x07)) /* identify bit in byte */
#define SET(bit) (A(bit) |= B(bit))
#define CLR(bit) (A(bit) &= (~B(bit)))
#define TST(bit) (A(bit) & B(bit))
/**************************************************************************/
static void pingstats(int junk)
{
int status;
signal(SIGINT, SIG_IGN);
printf("\n--- %s ping statistics ---\n", hostent->h_name);
printf("%lu packets transmitted, ", ntransmitted);
printf("%lu packets received, ", nreceived);
if (nrepeats)
printf("%lu duplicates, ", nrepeats);
if (ntransmitted)
printf("%lu%% packet loss\n",
(ntransmitted - nreceived) * 100 / ntransmitted);
if (nreceived)
printf("round-trip min/avg/max = %lu.%lu/%lu.%lu/%lu.%lu ms\n",
tmin / 10, tmin % 10,
(tsum / (nreceived + nrepeats)) / 10,
(tsum / (nreceived + nrepeats)) % 10, tmax / 10, tmax % 10);
if (nreceived != 0)
status = EXIT_SUCCESS;
else
status = EXIT_FAILURE;
exit(status);
}
static void sendping(int junk)
{
struct icmp *pkt;
int i;
char packet[datalen + ICMP_MINLEN];
pkt = (struct icmp *) packet;
pkt->icmp_type = ICMP_ECHO;
pkt->icmp_code = 0;
pkt->icmp_cksum = 0;
pkt->icmp_seq = htons(ntransmitted); /* don't ++ here, it can be a macro */
pkt->icmp_id = myid;
CLR((uint16_t)ntransmitted % MAX_DUP_CHK);
ntransmitted++;
gettimeofday((struct timeval *) &pkt->icmp_dun, NULL);
pkt->icmp_cksum = in_cksum((unsigned short *) pkt, sizeof(packet));
i = sendto(pingsock, packet, sizeof(packet), 0,
(struct sockaddr *) &pingaddr, sizeof(struct sockaddr_in));
if (i < 0)
bb_perror_msg_and_die("sendto");
if ((size_t)i != sizeof(packet))
bb_error_msg_and_die("ping wrote %d chars; %d expected", i,
(int)sizeof(packet));
signal(SIGALRM, sendping);
if (pingcount == 0 || ntransmitted < pingcount) { /* schedule next in 1s */
alarm(PINGINTERVAL);
} else { /* done, wait for the last ping to come back */
/* todo, don't necessarily need to wait so long... */
signal(SIGALRM, pingstats);
alarm(MAXWAIT);
}
}
static char *icmp_type_name(int id)
{
switch (id) {
case ICMP_ECHOREPLY: return "Echo Reply";
case ICMP_DEST_UNREACH: return "Destination Unreachable";
case ICMP_SOURCE_QUENCH: return "Source Quench";
case ICMP_REDIRECT: return "Redirect (change route)";
case ICMP_ECHO: return "Echo Request";
case ICMP_TIME_EXCEEDED: return "Time Exceeded";
case ICMP_PARAMETERPROB: return "Parameter Problem";
case ICMP_TIMESTAMP: return "Timestamp Request";
case ICMP_TIMESTAMPREPLY: return "Timestamp Reply";
case ICMP_INFO_REQUEST: return "Information Request";
case ICMP_INFO_REPLY: return "Information Reply";
case ICMP_ADDRESS: return "Address Mask Request";
case ICMP_ADDRESSREPLY: return "Address Mask Reply";
default: return "unknown ICMP type";
}
}
static void unpack(char *buf, int sz, struct sockaddr_in *from)
{
struct icmp *icmppkt;
struct iphdr *iphdr;
struct timeval tv, *tp;
int hlen, dupflag;
unsigned long triptime;
gettimeofday(&tv, NULL);
/* discard if too short */
if (sz < (datalen + ICMP_MINLEN))
return;
/* check IP header */
iphdr = (struct iphdr *) buf;
hlen = iphdr->ihl << 2;
sz -= hlen;
icmppkt = (struct icmp *) (buf + hlen);
if (icmppkt->icmp_id != myid)
return; /* not our ping */
if (icmppkt->icmp_type == ICMP_ECHOREPLY) {
uint16_t recv_seq = ntohs(icmppkt->icmp_seq);
++nreceived;
tp = (struct timeval *) icmppkt->icmp_data;
if ((tv.tv_usec -= tp->tv_usec) < 0) {
--tv.tv_sec;
tv.tv_usec += 1000000;
}
tv.tv_sec -= tp->tv_sec;
triptime = tv.tv_sec * 10000 + (tv.tv_usec / 100);
tsum += triptime;
if (triptime < tmin)
tmin = triptime;
if (triptime > tmax)
tmax = triptime;
if (TST(recv_seq % MAX_DUP_CHK)) {
++nrepeats;
--nreceived;
dupflag = 1;
} else {
SET(recv_seq % MAX_DUP_CHK);
dupflag = 0;
}
if (option_mask32 & OPT_QUIET)
return;
printf("%d bytes from %s: icmp_seq=%u", sz,
inet_ntoa(*(struct in_addr *) &from->sin_addr.s_addr),
recv_seq);
printf(" ttl=%d", iphdr->ttl);
printf(" time=%lu.%lu ms", triptime / 10, triptime % 10);
if (dupflag)
printf(" (DUP!)");
puts("");
} else {
if (icmppkt->icmp_type != ICMP_ECHO)
bb_error_msg("warning: got ICMP %d (%s)",
icmppkt->icmp_type,
icmp_type_name(icmppkt->icmp_type));
}
fflush(stdout);
}
static void ping(const char *host)
{
char packet[datalen + MAXIPLEN + MAXICMPLEN];
int sockopt;
pingsock = create_icmp_socket();
if (sourceaddr.sin_addr.s_addr) {
xbind(pingsock, (struct sockaddr*)&sourceaddr, sizeof(sourceaddr));
}
memset(&pingaddr, 0, sizeof(pingaddr));
pingaddr.sin_family = AF_INET;
hostent = xgethostbyname(host);
if (hostent->h_addrtype != AF_INET)
bb_error_msg_and_die("unknown address type; only AF_INET is currently supported");
memcpy(&pingaddr.sin_addr, hostent->h_addr, sizeof(pingaddr.sin_addr));
/* enable broadcast pings */
setsockopt_broadcast(pingsock);
/* set recv buf for broadcast pings */
sockopt = 48 * 1024; /* explain why 48k? */
setsockopt(pingsock, SOL_SOCKET, SO_RCVBUF, &sockopt, sizeof(sockopt));
printf("PING %s (%s)",
hostent->h_name,
inet_ntoa(*(struct in_addr *) &pingaddr.sin_addr.s_addr));
if (sourceaddr.sin_addr.s_addr) {
printf(" from %s",
inet_ntoa(*(struct in_addr *) &sourceaddr.sin_addr.s_addr));
}
printf(": %d data bytes\n", datalen);
signal(SIGINT, pingstats);
/* start the ping's going ... */
sendping(0);
/* listen for replies */
while (1) {
struct sockaddr_in from;
socklen_t fromlen = (socklen_t) sizeof(from);
int c;
c = recvfrom(pingsock, packet, sizeof(packet), 0,
(struct sockaddr *) &from, &fromlen);
if (c < 0) {
if (errno != EINTR)
bb_perror_msg("recvfrom");
continue;
}
unpack(packet, c, &from);
if (pingcount > 0 && nreceived >= pingcount)
break;
}
pingstats(0);
}
/* TODO: consolidate ether-wake.c, dnsd.c, ifupdown.c, nslookup.c
* versions of below thing. BTW we have far too many "%u.%u.%u.%u" too...
*/
static int parse_nipquad(const char *str, struct sockaddr_in* addr)
{
char dummy;
unsigned i1, i2, i3, i4;
if (sscanf(str, "%u.%u.%u.%u%c",
&i1, &i2, &i3, &i4, &dummy) == 4
&& ( (i1|i2|i3|i4) <= 0xff )
) {
uint8_t* ptr = (uint8_t*)&addr->sin_addr;
ptr[0] = i1;
ptr[1] = i2;
ptr[2] = i3;
ptr[3] = i4;
return 0;
}
return 1; /* error */
}
int ping_main(int argc, char **argv)
{
char *opt_c, *opt_s, *opt_I;
datalen = DEFDATALEN; /* initialized here rather than in global scope to work around gcc bug */
/* exactly one argument needed */
opt_complementary = "=1";
getopt32(argc, argv, OPT_STRING, &opt_c, &opt_s, &opt_I);
if (option_mask32 & 2) pingcount = xatoul(opt_c); // -c
if (option_mask32 & 4) datalen = xatou16(opt_s); // -s
if (option_mask32 & 8) { // -I
/* TODO: ping6 accepts iface too:
if_index = if_nametoindex(*argv);
if (!if_index) ...
make it true for ping. */
if (parse_nipquad(opt_I, &sourceaddr))
bb_show_usage();
}
myid = (int16_t) getpid();
ping(argv[optind]);
return EXIT_SUCCESS;
}
#endif /* ! CONFIG_FEATURE_FANCY_PING */