2 * owipcalc - OpenWrt IP Calculator
4 * Copyright (C) 2012 Jo-Philipp Wich <jow@openwrt.org>
6 * Licensed under the Apache License, Version 2.0 (the "License");
7 * you may not use this file except in compliance with the License.
8 * You may obtain a copy of the License at
10 * http://www.apache.org/licenses/LICENSE-2.0
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
27 #include <arpa/inet.h>
38 char v4[sizeof("255.255.255.255/255.255.255.255 ")];
39 char v6[sizeof("FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:255.255.255.255/128 ")];
48 bool (*a1)(struct cidr *a);
49 bool (*a2)(struct cidr *a, struct cidr *b);
52 bool (*a1)(struct cidr *a);
53 bool (*a2)(struct cidr *a, struct cidr *b);
58 static bool quiet = false;
59 static bool printed = false;
61 static struct cidr *stack = NULL;
63 #define qprintf(...) \
65 if (!quiet) printf(__VA_ARGS__); \
69 static void cidr_push(struct cidr *a)
78 static bool cidr_pop(struct cidr *a)
80 struct cidr *old = stack;
93 static struct cidr * cidr_clone(struct cidr *a)
95 struct cidr *b = malloc(sizeof(*b));
99 fprintf(stderr, "out of memory\n");
103 memcpy(b, a, sizeof(*b));
110 static struct cidr * cidr_parse4(const char *s)
114 struct cidr *addr = malloc(sizeof(struct cidr));
116 if (!addr || (strlen(s) >= sizeof(addr->buf.v4)))
119 snprintf(addr->buf.v4, sizeof(addr->buf.v4), "%s", s);
121 addr->family = AF_INET;
123 if ((p = strchr(addr->buf.v4, '/')) != NULL)
127 if (strchr(p, '.') != NULL)
129 if (inet_pton(AF_INET, p, &mask) != 1)
132 for (addr->prefix = 0; mask.s_addr; mask.s_addr >>= 1)
133 addr->prefix += (mask.s_addr & 1);
137 addr->prefix = strtoul(p, &r, 10);
139 if ((p == r) || (*r != 0) || (addr->prefix > 32))
148 if (p == addr->buf.v4+1)
149 memset(&addr->addr.v4, 0, sizeof(addr->addr.v4));
150 else if (inet_pton(AF_INET, addr->buf.v4, &addr->addr.v4) != 1)
162 static bool cidr_add4(struct cidr *a, struct cidr *b)
164 uint32_t x = ntohl(a->addr.v4.s_addr);
165 uint32_t y = ntohl(b->addr.v4.s_addr);
167 struct cidr *n = cidr_clone(a);
169 if ((n->family != AF_INET) || (b->family != AF_INET))
172 if ((uint32_t)(x + y) < x)
174 fprintf(stderr, "overflow during 'add'\n");
178 n->addr.v4.s_addr = htonl(x + y);
182 static bool cidr_sub4(struct cidr *a, struct cidr *b)
184 uint32_t x = ntohl(a->addr.v4.s_addr);
185 uint32_t y = ntohl(b->addr.v4.s_addr);
187 struct cidr *n = cidr_clone(a);
189 if ((n->family != AF_INET) || (b->family != AF_INET))
192 if ((uint32_t)(x - y) > x)
194 fprintf(stderr, "underflow during 'sub'\n");
198 n->addr.v4.s_addr = htonl(x - y);
202 static bool cidr_network4(struct cidr *a)
204 struct cidr *n = cidr_clone(a);
206 n->addr.v4.s_addr &= htonl(~((1 << (32 - n->prefix)) - 1));
212 static bool cidr_broadcast4(struct cidr *a)
214 struct cidr *n = cidr_clone(a);
216 n->addr.v4.s_addr |= htonl(((1 << (32 - n->prefix)) - 1));
222 static bool cidr_contains4(struct cidr *a, struct cidr *b)
224 uint32_t net1 = a->addr.v4.s_addr & htonl(~((1 << (32 - a->prefix)) - 1));
225 uint32_t net2 = b->addr.v4.s_addr & htonl(~((1 << (32 - a->prefix)) - 1));
230 if ((b->prefix >= a->prefix) && (net1 == net2))
242 static bool cidr_netmask4(struct cidr *a)
244 struct cidr *n = cidr_clone(a);
246 n->addr.v4.s_addr = htonl(~((1 << (32 - n->prefix)) - 1));
252 static bool cidr_private4(struct cidr *a)
254 uint32_t x = ntohl(a->addr.v4.s_addr);
259 if (((x >= 0x0A000000) && (x <= 0x0AFFFFFF)) ||
260 ((x >= 0xAC100000) && (x <= 0xAC1FFFFF)) ||
261 ((x >= 0xC0A80000) && (x <= 0xC0A8FFFF)))
273 static bool cidr_linklocal4(struct cidr *a)
275 uint32_t x = ntohl(a->addr.v4.s_addr);
280 if ((x >= 0xA9FE0000) && (x <= 0xA9FEFFFF))
292 static bool cidr_prev4(struct cidr *a, struct cidr *b)
294 struct cidr *n = cidr_clone(a);
296 n->prefix = b->prefix;
297 n->addr.v4.s_addr -= htonl(1 << (32 - b->prefix));
302 static bool cidr_next4(struct cidr *a, struct cidr *b)
304 struct cidr *n = cidr_clone(a);
306 n->prefix = b->prefix;
307 n->addr.v4.s_addr += htonl(1 << (32 - b->prefix));
312 static bool cidr_6to4(struct cidr *a)
314 struct cidr *n = cidr_clone(a);
315 uint32_t x = a->addr.v4.s_addr;
317 memset(&n->addr.v6.s6_addr, 0, sizeof(n->addr.v6.s6_addr));
319 n->family = AF_INET6;
322 n->addr.v6.s6_addr[0] = 0x20;
323 n->addr.v6.s6_addr[1] = 0x02;
324 n->addr.v6.s6_addr[2] = (x >> 24);
325 n->addr.v6.s6_addr[3] = (x >> 16) & 0xFF;
326 n->addr.v6.s6_addr[4] = (x >> 8) & 0xFF;
327 n->addr.v6.s6_addr[5] = x & 0xFF;
332 static bool cidr_print4(struct cidr *a)
336 if (!a || (a->family != AF_INET))
339 if (!(p = (char *)inet_ntop(AF_INET, &a->addr.v4, a->buf.v4, sizeof(a->buf.v4))))
348 qprintf("/%u", a->prefix);
356 static struct cidr * cidr_parse6(const char *s)
359 struct cidr *addr = malloc(sizeof(struct cidr));
361 if (!addr || (strlen(s) >= sizeof(addr->buf.v6)))
364 snprintf(addr->buf.v4, sizeof(addr->buf.v6), "%s", s);
366 addr->family = AF_INET6;
368 if ((p = strchr(addr->buf.v4, '/')) != NULL)
372 addr->prefix = strtoul(p, &r, 10);
374 if ((p == r) || (*r != 0) || (addr->prefix > 128))
382 if (p == addr->buf.v4+1)
383 memset(&addr->addr.v6, 0, sizeof(addr->addr.v6));
384 else if (inet_pton(AF_INET6, addr->buf.v4, &addr->addr.v6) != 1)
396 static bool cidr_add6(struct cidr *a, struct cidr *b)
398 uint8_t idx = 15, carry = 0, overflow = 0;
400 struct cidr *n = cidr_clone(a);
401 struct in6_addr *x = &n->addr.v6;
402 struct in6_addr *y = &b->addr.v6;
404 if ((a->family != AF_INET6) || (b->family != AF_INET6))
408 overflow = !!((x->s6_addr[idx] + y->s6_addr[idx] + carry) >= 256);
409 x->s6_addr[idx] += y->s6_addr[idx] + carry;
416 fprintf(stderr, "overflow during 'add'\n");
423 static bool cidr_sub6(struct cidr *a, struct cidr *b)
425 uint8_t idx = 15, carry = 0, underflow = 0;
427 struct cidr *n = cidr_clone(a);
428 struct in6_addr *x = &n->addr.v6;
429 struct in6_addr *y = &b->addr.v6;
431 if ((n->family != AF_INET6) || (b->family != AF_INET6))
435 underflow = !!((x->s6_addr[idx] - y->s6_addr[idx] - carry) < 0);
436 x->s6_addr[idx] -= y->s6_addr[idx] + carry;
443 fprintf(stderr, "underflow during 'sub'\n");
450 static bool cidr_prev6(struct cidr *a, struct cidr *b)
452 uint8_t idx, carry = 1, underflow = 0;
453 struct cidr *n = cidr_clone(a);
454 struct in6_addr *x = &n->addr.v6;
458 fprintf(stderr, "underflow during 'prev'\n");
462 idx = (b->prefix - 1) / 8;
465 underflow = !!((x->s6_addr[idx] - carry) < 0);
466 x->s6_addr[idx] -= carry;
473 fprintf(stderr, "underflow during 'prev'\n");
477 n->prefix = b->prefix;
482 static bool cidr_next6(struct cidr *a, struct cidr *b)
484 uint8_t idx, carry = 1, overflow = 0;
485 struct cidr *n = cidr_clone(a);
486 struct in6_addr *x = &n->addr.v6;
490 fprintf(stderr, "overflow during 'next'\n");
494 idx = (b->prefix - 1) / 8;
497 overflow = !!((x->s6_addr[idx] + carry) >= 256);
498 x->s6_addr[idx] += carry;
505 fprintf(stderr, "overflow during 'next'\n");
509 n->prefix = b->prefix;
514 static bool cidr_network6(struct cidr *a)
517 struct cidr *n = cidr_clone(a);
519 for (i = 0; i < (128 - n->prefix) / 8; i++)
520 n->addr.v6.s6_addr[15-i] = 0;
522 if ((128 - n->prefix) % 8)
523 n->addr.v6.s6_addr[15-i] &= ~((1 << ((128 - n->prefix) % 8)) - 1);
528 static bool cidr_contains6(struct cidr *a, struct cidr *b)
530 struct cidr *n = cidr_clone(a);
531 struct in6_addr *x = &n->addr.v6;
532 struct in6_addr *y = &b->addr.v6;
533 uint8_t i = (128 - n->prefix) / 8;
534 uint8_t m = ~((1 << ((128 - n->prefix) % 8)) - 1);
535 uint8_t net1 = x->s6_addr[15-i] & m;
536 uint8_t net2 = y->s6_addr[15-i] & m;
541 if ((b->prefix >= n->prefix) && (net1 == net2) &&
542 ((i == 15) || !memcmp(&x->s6_addr, &y->s6_addr, 15-i)))
554 static bool cidr_linklocal6(struct cidr *a)
559 if ((a->addr.v6.s6_addr[0] == 0xFE) &&
560 (a->addr.v6.s6_addr[1] >= 0x80) &&
561 (a->addr.v6.s6_addr[1] <= 0xBF))
573 static bool cidr_ula6(struct cidr *a)
578 if ((a->addr.v6.s6_addr[0] >= 0xFC) &&
579 (a->addr.v6.s6_addr[0] <= 0xFD))
591 static bool cidr_print6(struct cidr *a)
595 if (!a || (a->family != AF_INET6))
598 if (!(p = (char *)inet_ntop(AF_INET6, &a->addr.v6, a->buf.v6, sizeof(a->buf.v6))))
607 qprintf("/%u", a->prefix);
615 static struct cidr * cidr_parse(const char *op, const char *s, int af_hint)
621 uint32_t sum = strtoul(s, &r, 0);
623 if ((r > s) && (*r == 0))
625 a = malloc(sizeof(struct cidr));
630 if (af_hint == AF_INET)
634 a->addr.v4.s_addr = htonl(sum);
638 a->family = AF_INET6;
641 for (i = 0; i <= 15; i++)
643 a->addr.v6.s6_addr[15-i] = sum % 256;
659 if (a->family != af_hint)
661 fprintf(stderr, "attempt to '%s' %s with %s address\n",
663 (af_hint == AF_INET) ? "ipv4" : "ipv6",
664 (af_hint != AF_INET) ? "ipv4" : "ipv6");
671 static bool cidr_howmany(struct cidr *a, struct cidr *b)
676 if (b->prefix < a->prefix)
679 qprintf("%u", 1 << (b->prefix - a->prefix));
684 static bool cidr_prefix(struct cidr *a, struct cidr *b)
686 a->prefix = b->prefix;
690 static bool cidr_quiet(struct cidr *a)
699 .desc = "Add argument to base address",
701 .f6.a2 = cidr_add6 },
704 .desc = "Substract argument from base address",
706 .f6.a2 = cidr_sub6 },
709 .desc = "Advance base address to next prefix of given size",
711 .f6.a2 = cidr_next6 },
714 .desc = "Lower base address to previous prefix of give size",
716 .f6.a2 = cidr_prev6 },
719 .desc = "Turn base address into network address",
720 .f4.a1 = cidr_network4,
721 .f6.a1 = cidr_network6 },
723 { .name = "broadcast",
724 .desc = "Turn base address into broadcast address",
725 .f4.a1 = cidr_broadcast4 },
728 .desc = "Set the prefix of base address to argument",
729 .f4.a2 = cidr_prefix,
730 .f6.a2 = cidr_prefix },
733 .desc = "Calculate netmask of base address",
734 .f4.a1 = cidr_netmask4 },
737 .desc = "Calculate 6to4 prefix of given ipv4-address",
738 .f4.a1 = cidr_6to4 },
741 .desc = "Print amount of righ-hand prefixes that fit into base address",
742 .f4.a2 = cidr_howmany,
743 .f6.a2 = cidr_howmany },
745 { .name = "contains",
746 .desc = "Print '1' if argument fits into base address or '0' if not",
747 .f4.a2 = cidr_contains4,
748 .f6.a2 = cidr_contains6 },
751 .desc = "Print '1' if base address is in RFC1918 private space or '0' "
753 .f4.a1 = cidr_private4 },
755 { .name = "linklocal",
756 .desc = "Print '1' if base address is in 169.254.0.0/16 or FE80::/10 "
757 "link local space or '0' if not",
758 .f4.a1 = cidr_linklocal4,
759 .f6.a1 = cidr_linklocal6 },
762 .desc = "Print '1' if base address is in FC00::/7 unique local address "
763 "(ULA) space or '0' if not",
764 .f6.a1 = cidr_ula6 },
767 .desc = "Suppress output, useful for test operation where the result can "
768 "be inferred from the exit code",
770 .f6.a1 = cidr_quiet },
773 .desc = "Pop intermediate result from stack",
778 .desc = "Print intermediate result and pop it from stack, invoked "
779 "implicitely at the end of calculation if no intermediate prints "
781 .f4.a1 = cidr_print4,
782 .f6.a1 = cidr_print6 },
785 static void usage(const char *prog)
792 " %s {base address} operation [argument] "
793 "[operation [argument] ...]\n\n"
797 for (i = 0; i < sizeof(ops) / sizeof(ops[0]); i++)
799 if (ops[i].f4.a2 || ops[i].f6.a2)
801 fprintf(stderr, " %s %s\n",
803 (ops[i].f4.a2 && ops[i].f6.a2) ? "{ipv4/ipv6/amount}" :
804 (ops[i].f6.a2 ? "{ipv6/amount}" : "{ipv4/amount}"));
808 fprintf(stderr, " %s\n", ops[i].name);
811 fprintf(stderr, " %s.\n", ops[i].desc);
813 if ((ops[i].f4.a1 && ops[i].f6.a1) || (ops[i].f4.a2 && ops[i].f6.a2))
814 fprintf(stderr, " Applicable to ipv4- and ipv6-addresses.\n\n");
815 else if (ops[i].f6.a2 || ops[i].f6.a1)
816 fprintf(stderr, " Only applicable to ipv6-addresses.\n\n");
818 fprintf(stderr, " Only applicable to ipv4-addresses.\n\n");
823 " Calculate a DHCP range:\n\n"
824 " $ %s 192.168.1.1/255.255.255.0 network add 100 print add 150 print\n"
827 " Count number of prefixes:\n\n"
828 " $ %s 2001:0DB8:FDEF::/48 howmany ::/64\n"
835 static bool runop(char ***arg, int *status)
839 char *arg2 = *(*arg+1);
840 struct cidr *a = stack;
841 struct cidr *b = NULL;
846 for (i = 0; i < sizeof(ops) / sizeof(ops[0]); i++)
848 if (!strcmp(ops[i].name, arg1))
850 if (ops[i].f4.a2 || ops[i].f6.a2)
854 fprintf(stderr, "'%s' requires an argument\n",
861 b = cidr_parse(ops[i].name, arg2, a->family);
865 fprintf(stderr, "invalid address argument for '%s'\n",
874 if (((a->family == AF_INET) && !ops[i].f4.a2) ||
875 ((a->family == AF_INET6) && !ops[i].f6.a2))
877 fprintf(stderr, "'%s' not supported for %s addresses\n",
879 (a->family == AF_INET) ? "ipv4" : "ipv6");
885 *status = !((a->family == AF_INET) ? ops[i].f4.a2(a, b)
886 : ops[i].f6.a2(a, b));
894 if (((a->family == AF_INET) && !ops[i].f4.a1) ||
895 ((a->family == AF_INET6) && !ops[i].f6.a1))
897 fprintf(stderr, "'%s' not supported for %s addresses\n",
899 (a->family == AF_INET) ? "ipv4" : "ipv6");
905 *status = !((a->family == AF_INET) ? ops[i].f4.a1(a)
916 int main(int argc, char **argv)
925 a = strchr(argv[1], ':') ? cidr_parse6(argv[1]) : cidr_parse4(argv[1]);
932 while (runop(&arg, &status));
936 fprintf(stderr, "unknown operation '%s'\n", *arg);
940 if (!printed && (status < 2))
942 if (stack->family == AF_INET)