diff options
Diffstat (limited to 'toys/net/ping.c')
| -rw-r--r-- | toys/net/ping.c | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/toys/net/ping.c b/toys/net/ping.c new file mode 100644 index 00000000..cf1081af --- /dev/null +++ b/toys/net/ping.c @@ -0,0 +1,278 @@ +/* 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... + +// -s > 4088 = sizeof(toybuf)-sizeof(struct icmphdr), then kernel adds 20 bytes +USE_PING(NEWTOY(ping, "<1>1t#<0>255=64c#<0=3s#<0>4088=56I:i:W#<0=10w#<0qf46[-46]", 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 + -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; + + struct sockaddr *sa; + int sock; + long i_ms; + unsigned long sent, recv, fugit, min, max; +) + +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"); +} + +static void summary(int sig) +{ + if (!(toys.optflags&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); + printf("round-trip min/avg/max = %lu/%lu/%lu ms\n", + TT.min, TT.max, TT.fugit/TT.recv); + } + 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; +} + +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, len; + long long tnext, tW, tnow, tw; + unsigned short seq = 0, pkttime; + 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 = (toys.optflags&FLAG_f) ? 200 : 1000; + if (!(toys.optflags&FLAG_s)) TT.s = 56; // 64-PHDR_LEN + if ((toys.optflags&(FLAG_f|FLAG_c)) == FLAG_f) TT.c = 15; + + // 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; + + sigatexit(summary); + + // 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); + 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 (as root):\n"); + fprintf(stderr, "echo 0 9999999 > /proc/sys/net/ipv4/ping_group_range\n"); + } + xexit(); + } + 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(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); + } + 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) || !(TT.sent-TT.recv)) 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), TT.sa); + TT.sent++; + if ((toys.optflags&(FLAG_f|FLAG_q)) == FLAG_f) xputc('.'); + + // 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); + TT.recv++; + TT.fugit += (pkttime = millitime()-*(unsigned *)(ih+1)); + + // reply id == 0 for ipv4, 129 for ipv6 + + if (!(toys.optflags&FLAG_q)) { + if (toys.optflags&FLAG_f) xputc('\b'); + else { + printf("%d bytes from %s: icmp_seq=%d ttl=%d", len, ntop(sa2), + ih->un.echo.sequence, 0); + if (len >= sizeof(*ih)+4) + printf(" time=%u ms", pkttime); + xputc('\n'); + } + } + + toys.exitval = 0; + } + + summary(0); + + if (CFG_TOYBOX_FREE) { + freeaddrinfo(ai2); + if (ifa2) freeifaddrs(ifa2); + } +} |