| /* 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); |
| } |
| } |