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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 999999999 > /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...
- // -s > 4064 = sizeof(toybuf)-sizeof(struct icmphdr)-CMSG_SPACE(sizeof(uint8_t)), then kernel adds 20 bytes
- USE_PING(NEWTOY(ping, "<1>1m#t#<0>255=64c#<0=3s#<0>4064=56i%W#<0=3w#<0qf46I:[-46]", TOYFLAG_USR|TOYFLAG_BIN))
- USE_PING(OLDTOY(ping6, ping, TOYFLAG_USR|TOYFLAG_BIN))
-
- config PING
- bool "ping"
- default y
- 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 (print . and \b to show drops, default -c 15 -i 0.2)
- -i TIME Interval between packets (default 1, need root for < .2)
- -I IFACE/IP Source interface or address
- -m MARK Tag outgoing packets using SO_MARK
- -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 last -c packet (default 3)
- -w SEC Exit after this many seconds
- */
- #define FOR_ping
- #include "toys.h"
- #include <ifaddrs.h>
- #include <netinet/ip_icmp.h>
- GLOBALS(
- char *I;
- long w, W, i, s, c, t, m;
- struct sockaddr *sa;
- int sock;
- unsigned long sent, recv, fugit, min, max;
- )
- // Print a summary. Called as a single handler or at exit.
- static void summary(int sig)
- {
- if (!FLAG(q) && TT.sent && TT.sa) {
- printf("\n--- %s ping statistics ---\n", ntop(TT.sa));
- printf("%lu packets transmitted, %lu received, %ld%% packet loss\n",
- TT.sent, TT.recv, ((TT.sent-TT.recv)*100)/(TT.sent?TT.sent:1));
- if (TT.recv)
- printf("round-trip min/avg/max = %lu/%lu/%lu ms\n",
- TT.min, TT.fugit/TT.recv, TT.max);
- }
- TT.sa = 0;
- }
- // 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;
- }
- static int xrecvmsgwait(int fd, struct msghdr *msg, int flag,
- union socksaddr *sa, int timeout)
- {
- socklen_t sl = sizeof(*sa);
- int len;
- if (timeout >= 0) {
- struct pollfd pfd;
- pfd.fd = fd;
- pfd.events = POLLIN;
- if (!xpoll(&pfd, 1, timeout)) return 0;
- }
- msg->msg_name = (void *)sa;
- msg->msg_namelen = sl;
- len = recvmsg(fd, msg, flag);
- if (len<0) perror_exit("recvmsg");
- return len;
- }
- void ping_main(void)
- {
- struct addrinfo *ai, *ai2;
- struct ifaddrs *ifa, *ifa2 = 0;
- struct icmphdr *ih = (void *)toybuf;
- struct msghdr msg;
- struct cmsghdr *cmsg;
- struct iovec iov;
- union socksaddr srcaddr, srcaddr2;
- struct sockaddr *sa = (void *)&srcaddr;
- int family = 0, ttl = 0, len;
- long long tnext, tW, tnow, tw;
- unsigned short seq = 0, pkttime;
- // Set nonstatic default values
- if (!FLAG(i)) TT.i = FLAG(f) ? 200 : 1000;
- else if (TT.i<200 && geteuid()) error_exit("need root for -i <200");
- if (!FLAG(s)) TT.s = 56; // 64-PHDR_LEN
- if (FLAG(f) && !FLAG(c)) TT.c = 15;
- // ipv4 or ipv6? (0 = autodetect if -I or arg have only one address type.)
- if (FLAG(6) || strchr(toys.which->name, '6')) family = AF_INET6;
- else if (FLAG(4)) family = AF_INET;
- else family = 0;
- // If -I srcaddr look it up. Allow numeric address of correct type.
- memset(&srcaddr, 0, sizeof(srcaddr));
- if (TT.I) {
- if (!FLAG(6) && inet_pton(AF_INET, TT.I, (void *)&srcaddr.in.sin_addr))
- family = AF_INET;
- else if (!FLAG(4) && inet_pton(AF_INET6, TT.I, (void *)&srcaddr.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);
- TT.sa = ai->ai_addr;
- // Open DGRAM socket
- sa->sa_family = ai->ai_family;
- TT.sock = socket(ai->ai_family, SOCK_DGRAM,
- len = (ai->ai_family == AF_INET) ? IPPROTO_ICMP : IPPROTO_ICMPV6);
- if (TT.sock == -1) {
- perror_msg("socket SOCK_DGRAM %x", len);
- if (errno == EACCES) {
- fprintf(stderr, "Kernel bug workaround:\n"
- "echo 0 99999999 | sudo tee /proc/sys/net/ipv4/ping_group_range\n");
- }
- xexit();
- }
- if (TT.I) xbind(TT.sock, sa, sizeof(srcaddr));
- len = 1;
- xsetsockopt(TT.sock, SOL_IP, IP_RECVTTL, &len, sizeof(len));
- if (FLAG(m)) {
- len = TT.m;
- xsetsockopt(TT.sock, SOL_SOCKET, SO_MARK, &len, sizeof(len));
- }
- if (TT.t) {
- len = TT.t;
- if (ai->ai_family == AF_INET)
- xsetsockopt(TT.sock, IPPROTO_IP, IP_TTL, &len, 4);
- else xsetsockopt(TT.sock, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &len, sizeof(len));
- }
- if (!FLAG(q)) {
- printf("Ping %s (%s)", *toys.optargs, ntop(TT.sa));
- 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);
- }
- TT.min = ULONG_MAX;
- toys.exitval = 1;
- tW = tw = 0;
- tnext = millitime();
- if (TT.w) tw = TT.w*1000+tnext;
- memset(&msg, 0, sizeof(msg));
- // left enought space to store ttl value
- len = CMSG_SPACE(sizeof(uint8_t));
- iov.iov_base = (void *)toybuf;
- iov.iov_len = sizeof(toybuf) - len;
- msg.msg_iov = &iov;
- msg.msg_iovlen = 1;
- msg.msg_control = &toybuf[iov.iov_len];
- msg.msg_controllen = len;
- sigatexit(summary);
- // 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) || !(TT.sent-TT.recv)) break;
- waitms = tW-tnow;
- }
- if (tw) {
- if (tnow>tw) break;
- else if (waitms>tw-tnow) waitms = tw-tnow;
- }
- // Time to send the next packet?
- if (!tW && tnext-tnow <= 0) {
- tnext += TT.i;
- 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 = pingchksum((void *)toybuf, TT.s+sizeof(*ih));
- xsendto(TT.sock, toybuf, TT.s+sizeof(*ih), TT.sa);
- TT.sent++;
- if (FLAG(f) && !FLAG(q)) xputc('.');
- // last packet?
- if (TT.c) if (!--TT.c) {
- tW = tnow + TT.W*1000;
- waitms = 1; // check for immediate return even when W=0
- }
- }
- // 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;
- if (!(len = xrecvmsgwait(TT.sock, &msg, 0, &srcaddr2, waitms)))
- continue;
- TT.recv++;
- TT.fugit += (pkttime = millitime()-*(unsigned *)(ih+1));
- if (pkttime < TT.min) TT.min = pkttime;
- if (pkttime > TT.max) TT.max = pkttime;
- // reply id == 0 for ipv4, 129 for ipv6
- cmsg = CMSG_FIRSTHDR(&msg);
- for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
- if (cmsg->cmsg_level == IPPROTO_IP
- && cmsg->cmsg_type == IP_TTL) {
- ttl = *(uint8_t *)CMSG_DATA(cmsg);
- break;
- }
- };
- if (!FLAG(q)) {
- if (FLAG(f)) xputc('\b');
- else {
- printf("%d bytes from %s: icmp_seq=%d ttl=%d", len, ntop(&srcaddr2.s),
- ih->un.echo.sequence, ttl);
- if (len >= sizeof(*ih)+4) printf(" time=%u ms", pkttime);
- xputc('\n');
- }
- }
- toys.exitval = 0;
- }
- // summary(0) gets called for us atexit.
- if (CFG_TOYBOX_FREE) {
- freeaddrinfo(ai2);
- if (ifa2) freeifaddrs(ifa2);
- }
- }
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