/* vi: set sw=4 ts=4: */ /* * Mini ping implementation for busybox * * Copyright (C) 1999 by Randolph Chung * * 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. */ /* from ping6.c: * Copyright (C) 1999 by Randolph Chung * * This version of ping is adapted from the ping in netkit-base 0.10, * which is: * * Original copyright notice is retained at the end of this file. * * This version is an adaptation of ping.c from busybox. * The code was modified by Bart Visscher */ #include #include #include "libbb.h" enum { DEFDATALEN = 56, MAXIPLEN = 60, MAXICMPLEN = 76, MAXPACKET = 65468, MAX_DUP_CHK = (8 * 128), MAXWAIT = 10, PINGINTERVAL = 1, /* 1 second */ }; /* 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; } #if !ENABLE_FEATURE_FANCY_PING /* simple version */ static char *hostname; static void noresp(int ign ATTRIBUTE_UNUSED) { printf("No response from %s\n", hostname); exit(EXIT_FAILURE); } static void ping4(len_and_sockaddr *lsa) { struct sockaddr_in pingaddr; struct icmp *pkt; int pingsock, c; char packet[DEFDATALEN + MAXIPLEN + MAXICMPLEN]; pingsock = create_icmp_socket(); pingaddr = lsa->sin; 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 = xsendto(pingsock, packet, DEFDATALEN + ICMP_MINLEN, (struct sockaddr *) &pingaddr, sizeof(pingaddr)); /* 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); } int ping_main(int argc, char **argv); int ping_main(int argc, char **argv) { len_and_sockaddr *lsa; argv++; hostname = *argv; if (!hostname) bb_show_usage(); lsa = xhost_and_af2sockaddr(hostname, 0, AF_INET); /* Set timer _after_ DNS resolution */ signal(SIGALRM, noresp); alarm(5); /* give the host 5000ms to respond */ ping4(lsa); printf("%s is alive!\n", hostname); return EXIT_SUCCESS; } #else /* FEATURE_FANCY_PING */ /* full(er) version */ #define OPT_STRING ("qvc:s:I:4" USE_PING6("6")) enum { OPT_QUIET = 1 << 0, OPT_VERBOSE = 1 << 1, OPT_c = 1 << 2, OPT_s = 1 << 3, OPT_I = 1 << 4, OPT_IPV4 = 1 << 5, OPT_IPV6 = (1 << 6) * ENABLE_PING6, }; struct globals { int pingsock; len_and_sockaddr *source_lsa; unsigned datalen; int if_index; unsigned long ntransmitted, nreceived, nrepeats, pingcount; uint16_t myid; unsigned tmin, tmax; /* in us */ unsigned long long tsum; /* in us, sum of all times */ const char *hostname; const char *dotted; union { struct sockaddr sa; struct sockaddr_in sin; #if ENABLE_PING6 struct sockaddr_in6 sin6; #endif } pingaddr; char rcvd_tbl[MAX_DUP_CHK / 8]; }; #define G (*(struct globals*)&bb_common_bufsiz1) #define pingsock (G.pingsock ) #define source_lsa (G.source_lsa ) #define datalen (G.datalen ) #define if_index (G.if_index ) #define ntransmitted (G.ntransmitted) #define nreceived (G.nreceived ) #define nrepeats (G.nrepeats ) #define pingcount (G.pingcount ) #define myid (G.myid ) #define tmin (G.tmin ) #define tmax (G.tmax ) #define tsum (G.tsum ) #define hostname (G.hostname ) #define dotted (G.dotted ) #define pingaddr (G.pingaddr ) #define rcvd_tbl (G.rcvd_tbl ) void BUG_ping_globals_too_big(void); #define INIT_G() do { \ if (sizeof(G) > COMMON_BUFSIZE) \ BUG_ping_globals_too_big(); \ pingsock = -1; \ tmin = UINT_MAX; \ } while (0) #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 ATTRIBUTE_UNUSED) { signal(SIGINT, SIG_IGN); printf("\n--- %s ping statistics ---\n", hostname); printf("%lu packets transmitted, ", ntransmitted); printf("%lu packets received, ", nreceived); if (nrepeats) printf("%lu duplicates, ", nrepeats); if (ntransmitted) ntransmitted = (ntransmitted - nreceived) * 100 / ntransmitted; printf("%lu%% packet loss\n", ntransmitted); if (tmin != UINT_MAX) { unsigned tavg = tsum / (nreceived + nrepeats); printf("round-trip min/avg/max = %u.%03u/%u.%03u/%u.%03u ms\n", tmin / 1000, tmin % 1000, tavg / 1000, tavg % 1000, tmax / 1000, tmax % 1000); } exit(nreceived == 0); /* (nreceived == 0) is true (1) -- 'failure' */ } static void sendping_tail(void (*sp)(int), const void *pkt, int size_pkt) { int sz; CLR((uint16_t)ntransmitted % MAX_DUP_CHK); ntransmitted++; /* sizeof(pingaddr) can be larger than real sa size, but I think * it doesn't matter */ sz = xsendto(pingsock, pkt, size_pkt, &pingaddr.sa, sizeof(pingaddr)); if (sz != size_pkt) bb_error_msg_and_die(bb_msg_write_error); signal(SIGALRM, sp); 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 void sendping4(int junk ATTRIBUTE_UNUSED) { /* +4 reserves a place for timestamp, which may end up sitting * *after* packet. Saves one if() */ struct icmp *pkt = alloca(datalen + ICMP_MINLEN + 4); 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; /* We don't do hton, because we will read it back on the same machine */ /*if (datalen >= 4)*/ *(uint32_t*)&pkt->icmp_dun = monotonic_us(); pkt->icmp_cksum = in_cksum((unsigned short *) pkt, datalen + ICMP_MINLEN); sendping_tail(sendping4, pkt, datalen + ICMP_MINLEN); } static const 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_tail(int sz, uint32_t *tp, const char *from_str, uint16_t recv_seq, int ttl) { const char *dupmsg = " (DUP!)"; unsigned triptime = triptime; /* for gcc */ ++nreceived; if (tp) { /* (int32_t) cast is for hypothetical 64-bit unsigned */ /* (doesn't hurt 32-bit real-world anyway) */ triptime = (int32_t) ((uint32_t)monotonic_us() - *tp); tsum += triptime; if (triptime < tmin) tmin = triptime; if (triptime > tmax) tmax = triptime; } if (TST(recv_seq % MAX_DUP_CHK)) { ++nrepeats; --nreceived; } else { SET(recv_seq % MAX_DUP_CHK); dupmsg += 7; } if (option_mask32 & OPT_QUIET) return; printf("%d bytes from %s: seq=%u ttl=%d", sz, from_str, recv_seq, ttl); if (tp) printf(" time=%u.%03u ms", triptime / 1000, triptime % 1000); puts(dupmsg); fflush(stdout); } static void unpack4(char *buf, int sz, struct sockaddr_in *from) { struct icmp *icmppkt; struct iphdr *iphdr; int hlen; /* 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); uint32_t *tp = NULL; if (sz >= ICMP_MINLEN + sizeof(uint32_t)) tp = (uint32_t *) icmppkt->icmp_data; unpack_tail(sz, tp, inet_ntoa(*(struct in_addr *) &from->sin_addr.s_addr), recv_seq, iphdr->ttl); } else if (icmppkt->icmp_type != ICMP_ECHO) { bb_error_msg("warning: got ICMP %d (%s)", icmppkt->icmp_type, icmp_type_name(icmppkt->icmp_type)); } } static void ping4(len_and_sockaddr *lsa) { char packet[datalen + MAXIPLEN + MAXICMPLEN]; int sockopt; pingsock = create_icmp_socket(); pingaddr.sin = lsa->sin; if (source_lsa) { if (setsockopt(pingsock, IPPROTO_IP, IP_MULTICAST_IF, &source_lsa->sa, source_lsa->len)) bb_error_msg_and_die("can't set multicast source interface"); xbind(pingsock, &source_lsa->sa, source_lsa->len); } /* 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)); signal(SIGINT, pingstats); /* start the ping's going ... */ sendping4(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; } unpack4(packet, c, &from); if (pingcount > 0 && nreceived >= pingcount) break; } } static void ping(len_and_sockaddr *lsa) { printf("PING %s (%s)", hostname, dotted); if (source_lsa) { printf(" from %s", xmalloc_sockaddr2dotted_noport(&source_lsa->sa)); } printf(": %d data bytes\n", datalen); ping4(lsa); } int ping_main(int argc, char **argv); int ping_main(int argc, char **argv) { len_and_sockaddr *lsa; char *opt_c, *opt_s, *opt_I; USE_PING6(sa_family_t af = AF_UNSPEC;) INIT_G(); datalen = DEFDATALEN; /* initialized here rather than in global scope to work around gcc bug */ /* exactly one argument needed, -v and -q don't mix */ opt_complementary = "=1:q--v:v--q"; getopt32(argv, OPT_STRING, &opt_c, &opt_s, &opt_I); if (option_mask32 & OPT_c) pingcount = xatoul(opt_c); // -c if (option_mask32 & OPT_s) datalen = xatou16(opt_s); // -s if (option_mask32 & OPT_I) { // -I if_index = if_nametoindex(opt_I); if (!if_index) { /* TODO: I'm not sure it takes IPv6 unless in [XX:XX..] format */ source_lsa = xdotted2sockaddr(opt_I, 0); } } myid = (uint16_t) getpid(); hostname = argv[optind]; lsa = xhost_and_af2sockaddr(hostname, 0, AF_INET); if (source_lsa && source_lsa->sa.sa_family != lsa->sa.sa_family) /* leaking it here... */ source_lsa = NULL; dotted = xmalloc_sockaddr2dotted_noport(&lsa->sa); ping(lsa); pingstats(0); return EXIT_SUCCESS; } #endif /* FEATURE_FANCY_PING */