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/* ping.c - check network connectivity
*
* Copyright 2014 Rob Landley <rob@landley.net>
*
* Not in SUSv4.
*
* Note: ping_group_range should never have existed. To disable it, do:
* echo 0 $(((1<<31)-1)) > /proc/sys/net/ipv4/ping_group_range
* (Android does this by default in its init script.)
*
* Yes, I wimped out and capped -s at sizeof(toybuf), waiting for a complaint...
USE_PING(NEWTOY(ping, "<1>1t#<0>255=64c#<0=3s#<0>4088=56I:i:W#<0=10w#<0qf46[-46]", TOYFLAG_ROOTONLY|TOYFLAG_USR|TOYFLAG_BIN))
config PING
bool "ping"
default n
help
usage: ping [OPTIONS] HOST
Check network connectivity by sending packets to a host and reporting
its response.
Send ICMP ECHO_REQUEST packets to ipv4 or ipv6 addresses and prints each
echo it receives back, with round trip time. Returns true if host alive.
Options:
-4, -6 Force IPv4 or IPv6
-c CNT Send CNT many packets (default 3, 0 = infinite)
-f Flood (. on send, backspace on receive, to show packet drops)
-i TIME Interval between packets (default 1, need root for < .2)
-I IFACE/IP Source interface or address
-q Quiet (stops after one returns true if host is alive)
-s SIZE Data SIZE in bytes (default 56)
-t TTL Set Time To Live (number of hops)
-W SEC Seconds to wait for response after -c (default 10)
-w SEC Exit after this many seconds
*/
#define FOR_ping
#include "toys.h"
#include <ifaddrs.h>
#include <netinet/ip_icmp.h>
GLOBALS(
long w;
long W;
char *i;
char *I;
long s;
long c;
long t;
int sock;
long i_ms;
)
static void xsendto(int sockfd, void *buf, size_t len, struct sockaddr *dest)
{
int rc = sendto(TT.sock, buf, len, 0, dest,
dest->sa_family == AF_INET ? sizeof(struct sockaddr_in) :
sizeof(struct sockaddr_in6));
if (rc != len) perror_exit("sendto");
}
// assumes aligned and can read even number of bytes
static unsigned short pingchksum(unsigned short *data, int len)
{
unsigned short u = 0, d;
// circular carry is endian independent: bits from high byte go to low byte
while (len>0) {
d = *data++;
if (len == 1) d &= 255<<IS_BIG_ENDIAN;
if (d >= (u += d)) u++;
len -= 2;
}
return u;
}
void ping_main(void)
{
struct addrinfo *ai, *ai2;
struct ifaddrs *ifa, *ifa2 = 0;
union {
struct sockaddr_in in;
struct sockaddr_in6 in6;
} src_addr, src_addr2;
struct sockaddr *sa = (void *)&src_addr, *sa2 = (void *)&src_addr2;
struct pollfd pfd;
int family = 0, sent = 0, len;
long long tnext, tW, tnow, tw;
unsigned short seq = 0;
struct icmphdr *ih = (void *)toybuf;
// Interval
if (TT.i) {
long frac;
TT.i_ms = xparsetime(TT.i, 1000, &frac) * 1000;
TT.i_ms += frac;
if (TT.i_ms<200 && getuid()) error_exit("need root for -i <200");
} else TT.i_ms = 1000;
if (!(toys.optflags&FLAG_s)) TT.s = 56; // 64-PHDR_LEN
// ipv4 or ipv6? (0 = autodetect if -I or arg have only one address type.)
if (toys.optflags&FLAG_6) family = AF_INET6;
else if (toys.optflags&FLAG_4) family = AF_INET;
else family = 0;
// If -I src_addr look it up. Allow numeric address of correct type.
memset(&src_addr, 0, sizeof(src_addr));
if (TT.I) {
if (!(toys.optflags&FLAG_6) && inet_pton(AF_INET, TT.I,
(void *)&src_addr.in.sin_addr))
family = AF_INET;
else if (!(toys.optflags&FLAG_4) && inet_pton(AF_INET6, TT.I,
(void *)&src_addr.in6.sin6_addr))
family = AF_INET6;
else if (getifaddrs(&ifa2)) perror_exit("getifaddrs");
}
// Look up HOST address, filtering for correct type and interface.
// If -I but no -46 then find compatible type between -I and HOST
ai2 = xgetaddrinfo(*toys.optargs, 0, family, 0, 0, 0);
for (ai = ai2; ai; ai = ai->ai_next) {
// correct type?
if (family && family!=ai->ai_family) continue;
if (ai->ai_family!=AF_INET && ai->ai_family!=AF_INET6) continue;
// correct interface?
if (!TT.I || !ifa2) break;
for (ifa = ifa2; ifa; ifa = ifa->ifa_next) {
if (!ifa->ifa_addr || ifa->ifa_addr->sa_family!=ai->ai_family
|| strcmp(ifa->ifa_name, TT.I)) continue;
sa = (void *)ifa->ifa_addr;
break;
}
if (ifa) break;
}
if (!ai)
error_exit("no v%d addr for -I %s", 4+2*(family==AF_INET6), TT.I);
// Open DGRAM socket
sa->sa_family = ai->ai_family;
TT.sock = xsocket(ai->ai_family, SOCK_DGRAM,
(ai->ai_family == AF_INET) ? IPPROTO_ICMP : IPPROTO_ICMPV6);
if (TT.I && bind(TT.sock, sa, sizeof(src_addr))) perror_exit("bind");
if (TT.t) {
len = TT.t;
if (ai->ai_family == AF_INET)
setsockopt(TT.sock, IPPROTO_IP, IP_TTL, &len, 4);
else setsockopt(TT.sock, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &len, 4);
}
if (!(toys.optflags&FLAG_q)) {
printf("Ping %s (%s)", *toys.optargs, ntop(ai->ai_addr));
if (TT.I) {
*toybuf = 0;
printf(" from %s (%s)", TT.I, ntop(sa));
}
// 20 byte TCP header, 8 byte ICMP header, plus data payload
printf(": %ld(%ld) bytes.\n", TT.s, TT.s+28);
}
toys.exitval = 1;
tW = tw = 0;
tnext = millitime();
if (TT.w) tw = TT.w*1000+tnext;
// Send/receive packets
for (;;) {
int waitms = INT_MAX;
// Exit due to timeout? (TODO: timeout is after last packet, waiting if
// any packets ever dropped. Not timeout since packet was dropped.)
tnow = millitime();
if (tW) if (0>=(waitms = tW-tnow) || !sent) break;
if (tw) {
if (tnow>tw) break;
else if (waitms>tw-tnow) waitms = tw-tnow;
// Time to send the next packet?
} else if (tnext-tnow <= 0) {
tnext += TT.i_ms;
memset(ih, 0, sizeof(*ih));
ih->type = (ai->ai_family == AF_INET) ? 8 : 128;
ih->un.echo.id = getpid();
ih->un.echo.sequence = ++seq;
if (TT.s >= 4) *(unsigned *)(ih+1) = tnow;
ih->checksum = 0;
ih->checksum = pingchksum((void *)toybuf, TT.s+sizeof(*ih));
xsendto(TT.sock, toybuf, TT.s+sizeof(*ih), ai->ai_addr);
sent++;
if (toys.optflags&FLAG_f) printf(".");
// last packet?
if (TT.c) if (!--TT.c) {
if (!TT.W) break;
tW = tnow + TT.W*1000;
}
}
// This is down here so it's against new period if we just sent a packet
if (!tw && waitms>tnext-tnow) waitms = tnext-tnow;
// wait for next packet or timeout
if (waitms<0) waitms = 0;
pfd.fd = TT.sock;
pfd.events = POLLIN;
if (0>(len = poll(&pfd, 1, waitms))) break;
if (!len) continue;
len = sizeof(src_addr2);
len = recvfrom(TT.sock, toybuf, sizeof(toybuf), 0, sa2, (void *)&len);
sent--;
// reply id == 0 for ipv4, 129 for ipv6
if (!(toys.optflags&FLAG_q)) {
printf("%d bytes from %s: icmp_seq=%d ttl=%d", len, ntop(sa2),
ih->un.echo.sequence, 0);
if (len >= sizeof(*ih)+4) {
unsigned lunchtime = millitime()-*(unsigned *)(ih+1);
printf(" time=%u.%03u", lunchtime/1000, lunchtime%1000);
}
xputc('\n');
}
toys.exitval = 0;
}
if (CFG_TOYBOX_FREE) {
freeaddrinfo(ai2);
if (ifa2) freeifaddrs(ifa2);
}
}
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