1 /* ping.c - check network connectivity 2 * 3 * Copyright 2014 Rob Landley <rob (at) landley.net> 4 * 5 * Not in SUSv4. 6 * 7 * Note: ping_group_range should never have existed. To disable it, do: 8 * echo 0 $(((1<<31)-1)) > /proc/sys/net/ipv4/ping_group_range 9 * (Android does this by default in its init script.) 10 * 11 * Yes, I wimped out and capped -s at sizeof(toybuf), waiting for a complaint... 12 13 // -s > 4088 = sizeof(toybuf)-sizeof(struct icmphdr), then kernel adds 20 bytes 14 USE_PING(NEWTOY(ping, "<1>1m#t#<0>255=64c#<0=3s#<0>4088=56i%W#<0=3w#<0qf46I:[-46]", TOYFLAG_USR|TOYFLAG_BIN)) 15 USE_PING(OLDTOY(ping6, ping, TOYFLAG_USR|TOYFLAG_BIN)) 16 17 config PING 18 bool "ping" 19 default y 20 help 21 usage: ping [OPTIONS] HOST 22 23 Check network connectivity by sending packets to a host and reporting 24 its response. 25 26 Send ICMP ECHO_REQUEST packets to ipv4 or ipv6 addresses and prints each 27 echo it receives back, with round trip time. Returns true if host alive. 28 29 Options: 30 -4, -6 Force IPv4 or IPv6 31 -c CNT Send CNT many packets (default 3, 0 = infinite) 32 -f Flood (print . and \b to show drops, default -c 15 -i 0.2) 33 -i TIME Interval between packets (default 1, need root for < .2) 34 -I IFACE/IP Source interface or address 35 -m MARK Tag outgoing packets using SO_MARK 36 -q Quiet (stops after one returns true if host is alive) 37 -s SIZE Data SIZE in bytes (default 56) 38 -t TTL Set Time To Live (number of hops) 39 -W SEC Seconds to wait for response after last -c packet (default 3) 40 -w SEC Exit after this many seconds 41 */ 42 43 #define FOR_ping 44 #include "toys.h" 45 46 #include <ifaddrs.h> 47 #include <netinet/ip_icmp.h> 48 49 GLOBALS( 50 char *I; 51 long w, W, i, s, c, t, m; 52 53 struct sockaddr *sa; 54 int sock; 55 unsigned long sent, recv, fugit, min, max; 56 ) 57 58 // Print a summary. Called as a single handler or at exit. 59 static void summary(int sig) 60 { 61 if (!(toys.optflags&FLAG_q) && TT.sent && TT.sa) { 62 printf("\n--- %s ping statistics ---\n", ntop(TT.sa)); 63 printf("%lu packets transmitted, %lu received, %ld%% packet loss\n", 64 TT.sent, TT.recv, ((TT.sent-TT.recv)*100)/(TT.sent?TT.sent:1)); 65 printf("round-trip min/avg/max = %lu/%lu/%lu ms\n", 66 TT.min, TT.max, TT.fugit/(TT.recv?TT.recv:1)); 67 } 68 TT.sa = 0; 69 } 70 71 // assumes aligned and can read even number of bytes 72 static unsigned short pingchksum(unsigned short *data, int len) 73 { 74 unsigned short u = 0, d; 75 76 // circular carry is endian independent: bits from high byte go to low byte 77 while (len>0) { 78 d = *data++; 79 if (len == 1) d &= 255<<IS_BIG_ENDIAN; 80 if (d >= (u += d)) u++; 81 len -= 2; 82 } 83 84 return u; 85 } 86 87 void ping_main(void) 88 { 89 struct addrinfo *ai, *ai2; 90 struct ifaddrs *ifa, *ifa2 = 0; 91 struct icmphdr *ih = (void *)toybuf; 92 union socksaddr srcaddr, srcaddr2; 93 struct sockaddr *sa = (void *)&srcaddr; 94 int family = 0, len; 95 long long tnext, tW, tnow, tw; 96 unsigned short seq = 0, pkttime; 97 98 // Set nonstatic default values 99 if (!(toys.optflags&FLAG_i)) TT.i = (toys.optflags&FLAG_f) ? 200 : 1000; 100 else if (TT.i<200 && getuid()) error_exit("need root for -i <200"); 101 if (!(toys.optflags&FLAG_s)) TT.s = 56; // 64-PHDR_LEN 102 if ((toys.optflags&(FLAG_f|FLAG_c)) == FLAG_f) TT.c = 15; 103 104 // ipv4 or ipv6? (0 = autodetect if -I or arg have only one address type.) 105 if (FLAG(6) || strchr(toys.which->name, '6')) family = AF_INET6; 106 else if (FLAG(4)) family = AF_INET; 107 else family = 0; 108 109 // If -I srcaddr look it up. Allow numeric address of correct type. 110 memset(&srcaddr, 0, sizeof(srcaddr)); 111 if (TT.I) { 112 if (!(toys.optflags&FLAG_6) && inet_pton(AF_INET, TT.I, 113 (void *)&srcaddr.in.sin_addr)) 114 family = AF_INET; 115 else if (!(toys.optflags&FLAG_4) && inet_pton(AF_INET6, TT.I, 116 (void *)&srcaddr.in6.sin6_addr)) 117 family = AF_INET6; 118 else if (getifaddrs(&ifa2)) perror_exit("getifaddrs"); 119 } 120 121 // Look up HOST address, filtering for correct type and interface. 122 // If -I but no -46 then find compatible type between -I and HOST 123 ai2 = xgetaddrinfo(*toys.optargs, 0, family, 0, 0, 0); 124 for (ai = ai2; ai; ai = ai->ai_next) { 125 126 // correct type? 127 if (family && family!=ai->ai_family) continue; 128 if (ai->ai_family!=AF_INET && ai->ai_family!=AF_INET6) continue; 129 130 // correct interface? 131 if (!TT.I || !ifa2) break; 132 for (ifa = ifa2; ifa; ifa = ifa->ifa_next) { 133 if (!ifa->ifa_addr || ifa->ifa_addr->sa_family!=ai->ai_family 134 || strcmp(ifa->ifa_name, TT.I)) continue; 135 sa = (void *)ifa->ifa_addr; 136 137 break; 138 } 139 if (ifa) break; 140 } 141 142 if (!ai) 143 error_exit("no v%d addr for -I %s", 4+2*(family==AF_INET6), TT.I); 144 TT.sa = ai->ai_addr; 145 146 // Open DGRAM socket 147 sa->sa_family = ai->ai_family; 148 TT.sock = socket(ai->ai_family, SOCK_DGRAM, 149 len = (ai->ai_family == AF_INET) ? IPPROTO_ICMP : IPPROTO_ICMPV6); 150 if (TT.sock == -1) { 151 perror_msg("socket SOCK_DGRAM %x", len); 152 if (errno == EACCES) { 153 fprintf(stderr, "Kernel bug workaround (as root):\n"); 154 fprintf(stderr, "echo 0 9999999 > /proc/sys/net/ipv4/ping_group_range\n"); 155 } 156 xexit(); 157 } 158 if (TT.I && bind(TT.sock, sa, sizeof(srcaddr))) perror_exit("bind"); 159 160 if (toys.optflags&FLAG_m) { 161 int mark = TT.m; 162 163 xsetsockopt(TT.sock, SOL_SOCKET, SO_MARK, &mark, sizeof(mark)); 164 } 165 166 if (TT.t) { 167 len = TT.t; 168 169 if (ai->ai_family == AF_INET) 170 xsetsockopt(TT.sock, IPPROTO_IP, IP_TTL, &len, 4); 171 else xsetsockopt(TT.sock, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &len, 4); 172 } 173 174 if (!(toys.optflags&FLAG_q)) { 175 printf("Ping %s (%s)", *toys.optargs, ntop(TT.sa)); 176 if (TT.I) { 177 *toybuf = 0; 178 printf(" from %s (%s)", TT.I, ntop(sa)); 179 } 180 // 20 byte TCP header, 8 byte ICMP header, plus data payload 181 printf(": %ld(%ld) bytes.\n", TT.s, TT.s+28); 182 } 183 toys.exitval = 1; 184 185 tW = tw = 0; 186 tnext = millitime(); 187 if (TT.w) tw = TT.w*1000+tnext; 188 189 sigatexit(summary); 190 191 // Send/receive packets 192 for (;;) { 193 int waitms = INT_MAX; 194 195 // Exit due to timeout? (TODO: timeout is after last packet, waiting if 196 // any packets ever dropped. Not timeout since packet was dropped.) 197 tnow = millitime(); 198 if (tW) { 199 if (0>=(waitms = tW-tnow) || !(TT.sent-TT.recv)) break; 200 waitms = tW-tnow; 201 } 202 if (tw) { 203 if (tnow>tw) break; 204 else if (waitms>tw-tnow) waitms = tw-tnow; 205 } 206 207 // Time to send the next packet? 208 if (!tW && tnext-tnow <= 0) { 209 tnext += TT.i; 210 211 memset(ih, 0, sizeof(*ih)); 212 ih->type = (ai->ai_family == AF_INET) ? 8 : 128; 213 ih->un.echo.id = getpid(); 214 ih->un.echo.sequence = ++seq; 215 if (TT.s >= 4) *(unsigned *)(ih+1) = tnow; 216 217 ih->checksum = 0; 218 ih->checksum = pingchksum((void *)toybuf, TT.s+sizeof(*ih)); 219 xsendto(TT.sock, toybuf, TT.s+sizeof(*ih), TT.sa); 220 TT.sent++; 221 if ((toys.optflags&(FLAG_f|FLAG_q)) == FLAG_f) xputc('.'); 222 223 // last packet? 224 if (TT.c) if (!--TT.c) { 225 tW = tnow + TT.W*1000; 226 waitms = 1; // check for immediate return even when W=0 227 } 228 } 229 230 // This is down here so it's against new period if we just sent a packet 231 if (!tW && waitms>tnext-tnow) waitms = tnext-tnow; 232 233 // wait for next packet or timeout 234 235 if (waitms<0) waitms = 0; 236 if (!(len = xrecvwait(TT.sock, toybuf, sizeof(toybuf), &srcaddr2, waitms))) 237 continue; 238 239 TT.recv++; 240 TT.fugit += (pkttime = millitime()-*(unsigned *)(ih+1)); 241 242 // reply id == 0 for ipv4, 129 for ipv6 243 244 if (!(toys.optflags&FLAG_q)) { 245 if (toys.optflags&FLAG_f) xputc('\b'); 246 else { 247 printf("%d bytes from %s: icmp_seq=%d ttl=%d", len, ntop(&srcaddr2.s), 248 ih->un.echo.sequence, 0); 249 if (len >= sizeof(*ih)+4) 250 printf(" time=%u ms", pkttime); 251 xputc('\n'); 252 } 253 } 254 255 toys.exitval = 0; 256 } 257 258 sigatexit(0); 259 summary(0); 260 261 if (CFG_TOYBOX_FREE) { 262 freeaddrinfo(ai2); 263 if (ifa2) freeifaddrs(ifa2); 264 } 265 } 266
