--- /dev/null
+/*
+ * owipcalc - OpenWrt IP Calculator
+ *
+ * Copyright (C) 2012 Jo-Philipp Wich <jow@openwrt.org>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdlib.h>
+
+#include <string.h>
+#include <unistd.h>
+
+#include <arpa/inet.h>
+
+
+struct cidr {
+ uint8_t family;
+ uint32_t prefix;
+ union {
+ struct in_addr v4;
+ struct in6_addr v6;
+ } addr;
+ union {
+ char v4[sizeof("255.255.255.255/255.255.255.255 ")];
+ char v6[sizeof("FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF/128 ")];
+ } buf;
+};
+
+struct op {
+ const char *name;
+ const char *desc;
+ struct {
+ bool (*a1)(struct cidr *a);
+ bool (*a2)(struct cidr *a, struct cidr *b);
+ } f4;
+ struct {
+ bool (*a1)(struct cidr *a);
+ bool (*a2)(struct cidr *a, struct cidr *b);
+ } f6;
+};
+
+
+static bool quiet = false;
+static bool printed = false;
+
+
+static struct cidr * cidr_parse4(const char *s)
+{
+ char *p = NULL, *r;
+ struct in_addr mask;
+ struct cidr *addr = malloc(sizeof(struct cidr));
+
+ if (!addr || (strlen(s) >= sizeof(addr->buf.v4)))
+ goto err;
+
+ snprintf(addr->buf.v4, sizeof(addr->buf.v4), "%s", s);
+
+ addr->family = AF_INET;
+
+ if ((p = strchr(addr->buf.v4, '/')) != NULL)
+ {
+ *p++ = 0;
+
+ if (strchr(p, '.') != NULL)
+ {
+ if (inet_pton(AF_INET, p, &mask) != 1)
+ goto err;
+
+ for (addr->prefix = 0; mask.s_addr; mask.s_addr >>= 1)
+ addr->prefix += (mask.s_addr & 1);
+ }
+ else
+ {
+ addr->prefix = strtoul(p, &r, 10);
+
+ if ((p == r) || (*r != 0) || (addr->prefix > 32))
+ goto err;
+ }
+ }
+ else
+ {
+ addr->prefix = 32;
+ }
+
+ if (p == addr->buf.v4+1)
+ memset(&addr->addr.v4, 0, sizeof(addr->addr.v4));
+ else if (inet_pton(AF_INET, addr->buf.v4, &addr->addr.v4) != 1)
+ goto err;
+
+ return addr;
+
+err:
+ if (addr)
+ free(addr);
+
+ return NULL;
+}
+
+static bool cidr_add4(struct cidr *a, struct cidr *b)
+{
+ uint32_t x = ntohl(a->addr.v4.s_addr);
+ uint32_t y = ntohl(b->addr.v4.s_addr);
+
+ if ((a->family != AF_INET) || (b->family != AF_INET))
+ return false;
+
+ if ((uint32_t)(x + y) < x)
+ {
+ fprintf(stderr, "overflow during 'add'\n");
+ return false;
+ }
+
+ a->addr.v4.s_addr = htonl(x + y);
+ return true;
+}
+
+static bool cidr_sub4(struct cidr *a, struct cidr *b)
+{
+ uint32_t x = ntohl(a->addr.v4.s_addr);
+ uint32_t y = ntohl(b->addr.v4.s_addr);
+
+ if ((a->family != AF_INET) || (b->family != AF_INET))
+ return false;
+
+ if ((uint32_t)(x - y) > x)
+ {
+ fprintf(stderr, "underflow during 'sub'\n");
+ return false;
+ }
+
+ a->addr.v4.s_addr = htonl(x - y);
+ return true;
+}
+
+static bool cidr_network4(struct cidr *a)
+{
+ a->addr.v4.s_addr &= htonl(~((1 << (32 - a->prefix)) - 1));
+ a->prefix = 32;
+ return true;
+}
+
+static bool cidr_broadcast4(struct cidr *a)
+{
+ a->addr.v4.s_addr |= htonl(((1 << (32 - a->prefix)) - 1));
+ a->prefix = 32;
+ return true;
+}
+
+static bool cidr_contains4(struct cidr *a, struct cidr *b)
+{
+ uint32_t net1 = a->addr.v4.s_addr & htonl(~((1 << (32 - a->prefix)) - 1));
+ uint32_t net2 = b->addr.v4.s_addr & htonl(~((1 << (32 - a->prefix)) - 1));
+
+ printed = true;
+
+ if ((b->prefix >= a->prefix) && (net1 == net2))
+ {
+ if (!quiet) printf("1\n");
+ return true;
+ }
+ else
+ {
+ if (!quiet) printf("0\n");
+ return false;
+ }
+}
+
+static bool cidr_netmask4(struct cidr *a)
+{
+ struct in_addr mask;
+ char buf[sizeof("255.255.255.255 ")];
+
+ mask.s_addr = htonl(~((1 << (32 - a->prefix)) - 1));
+
+ if (!quiet)
+ printf("%s\n", inet_ntop(AF_INET, &mask, buf, sizeof(buf)));
+
+ printed = true;
+
+ return true;
+}
+
+static bool cidr_private4(struct cidr *a)
+{
+ uint32_t x = ntohl(a->addr.v4.s_addr);
+
+ printed = true;
+
+ if (((x >= 0x0A000000) && (x <= 0x0AFFFFFF)) ||
+ ((x >= 0xAC100000) && (x <= 0xAC1FFFFF)) ||
+ ((x >= 0xC0A80000) && (x <= 0xC0A8FFFF)))
+ {
+ if (!quiet) printf("1\n");
+ return true;
+ }
+ else
+ {
+ if (!quiet) printf("0\n");
+ return false;
+ }
+}
+
+static bool cidr_linklocal4(struct cidr *a)
+{
+ uint32_t x = ntohl(a->addr.v4.s_addr);
+
+ printed = true;
+
+ if ((x >= 0xA9FE0000) && (x <= 0xA9FEFFFF))
+ {
+ if (!quiet) printf("1\n");
+ return true;
+ }
+ else
+ {
+ if (!quiet) printf("0\n");
+ return false;
+ }
+}
+
+static bool cidr_print4(struct cidr *a)
+{
+ char *p;
+
+ if (a->family != AF_INET)
+ return false;
+
+ if (!(p = (char *)inet_ntop(AF_INET, &a->addr.v4, a->buf.v4, sizeof(a->buf.v4))))
+ return false;
+
+ if (!quiet)
+ printf("%s", p);
+
+ if (!quiet && (a->prefix < 32))
+ printf("/%u", a->prefix);
+
+ if (!quiet)
+ printf("\n");
+
+ printed = true;
+
+ return true;
+}
+
+
+static struct cidr * cidr_parse6(const char *s)
+{
+ char *p = NULL, *r;
+ struct cidr *addr = malloc(sizeof(struct cidr));
+
+ if (!addr || (strlen(s) >= sizeof(addr->buf.v6)))
+ goto err;
+
+ snprintf(addr->buf.v6, sizeof(addr->buf.v6), "%s", s);
+
+ addr->family = AF_INET6;
+
+ if ((p = strchr(addr->buf.v6, '/')) != NULL)
+ {
+ *p++ = 0;
+
+ addr->prefix = strtoul(p, &r, 10);
+
+ if ((p == r) || (*r != 0) || (addr->prefix > 128))
+ goto err;
+ }
+ else
+ {
+ addr->prefix = 128;
+ }
+
+ if (p == addr->buf.v6+1)
+ memset(&addr->addr.v6, 0, sizeof(addr->addr.v6));
+ else if (inet_pton(AF_INET6, addr->buf.v6, &addr->addr.v6) != 1)
+ goto err;
+
+ return addr;
+
+err:
+ if (addr)
+ free(addr);
+
+ return NULL;
+}
+
+static bool cidr_add6(struct cidr *a, struct cidr *b)
+{
+ uint8_t idx = 15, carry = 0, overflow = 0;
+
+ struct in6_addr *x = &a->addr.v6;
+ struct in6_addr *y = &b->addr.v6;
+
+ if ((a->family != AF_INET6) || (b->family != AF_INET6))
+ return false;
+
+ do {
+ overflow = !!((x->s6_addr[idx] + y->s6_addr[idx] + carry) >= 256);
+ x->s6_addr[idx] += y->s6_addr[idx] + carry;
+ carry = overflow;
+ }
+ while (idx-- > 0);
+
+ if (carry)
+ {
+ fprintf(stderr, "overflow during 'add'\n");
+ return false;
+ }
+
+ return true;
+}
+
+static bool cidr_sub6(struct cidr *a, struct cidr *b)
+{
+ uint8_t idx = 15, carry = 0, underflow = 0;
+
+ struct in6_addr *x = &a->addr.v6;
+ struct in6_addr *y = &b->addr.v6;
+
+ if ((a->family != AF_INET6) || (b->family != AF_INET6))
+ return false;
+
+ do {
+ underflow = !!((x->s6_addr[idx] - y->s6_addr[idx] - carry) < 0);
+ x->s6_addr[idx] -= y->s6_addr[idx] + carry;
+ carry = underflow;
+ }
+ while (idx-- > 0);
+
+ if (carry)
+ {
+ fprintf(stderr, "underflow during 'sub'\n");
+ return false;
+ }
+
+ return true;
+}
+
+static bool cidr_network6(struct cidr *a)
+{
+ uint8_t i;
+
+ for (i = 0; i < (128 - a->prefix) / 8; i++)
+ a->addr.v6.s6_addr[15-i] = 0;
+
+ if ((128 - a->prefix) % 8)
+ a->addr.v6.s6_addr[15-i] &= ~((1 << ((128 - a->prefix) % 8)) - 1);
+
+ return true;
+}
+
+static bool cidr_contains6(struct cidr *a, struct cidr *b)
+{
+ struct in6_addr *x = &a->addr.v6;
+ struct in6_addr *y = &b->addr.v6;
+
+ uint8_t i = (128 - a->prefix) / 8;
+ uint8_t m = ~((1 << ((128 - a->prefix) % 8)) - 1);
+ uint8_t net1 = x->s6_addr[15-i] & m;
+ uint8_t net2 = y->s6_addr[15-i] & m;
+
+ printed = true;
+
+ if ((b->prefix >= a->prefix) && (net1 == net2) &&
+ ((i == 15) || !memcmp(&x->s6_addr, &y->s6_addr, 15-i)))
+ {
+ if (!quiet) printf("1\n");
+ return true;
+ }
+ else
+ {
+ if (!quiet) printf("0\n");
+ return false;
+ }
+}
+
+static bool cidr_linklocal6(struct cidr *a)
+{
+ printed = true;
+
+ if ((a->addr.v6.s6_addr[0] == 0xFE) &&
+ (a->addr.v6.s6_addr[1] >= 0x80) &&
+ (a->addr.v6.s6_addr[1] <= 0xBF))
+ {
+ if (!quiet) printf("1\n");
+ return true;
+ }
+ else
+ {
+ if (!quiet) printf("0\n");
+ return false;
+ }
+}
+
+static bool cidr_ula6(struct cidr *a)
+{
+ printed = true;
+
+ if ((a->addr.v6.s6_addr[0] >= 0xFC) &&
+ (a->addr.v6.s6_addr[0] <= 0xFD))
+ {
+ if (!quiet) printf("1\n");
+ return true;
+ }
+ else
+ {
+ if (!quiet) printf("0\n");
+ return false;
+ }
+}
+
+static bool cidr_print6(struct cidr *a)
+{
+ char *p;
+
+ if (a->family != AF_INET6)
+ return NULL;
+
+ if (!(p = (char *)inet_ntop(AF_INET6, &a->addr.v6, a->buf.v6, sizeof(a->buf.v6))))
+ return false;
+
+ if (!quiet)
+ printf("%s", p);
+
+ if (!quiet && (a->prefix < 128))
+ printf("/%u", a->prefix);
+
+ if (!quiet)
+ printf("\n");
+
+ printed = true;
+
+ return true;
+}
+
+
+static struct cidr * cidr_parse(const char *op, const char *s, int af_hint)
+{
+ char *r;
+ struct cidr *a;
+
+ uint8_t i;
+ uint32_t sum = strtoul(s, &r, 0);
+
+ if ((r > s) && (*r == 0))
+ {
+ a = malloc(sizeof(struct cidr));
+
+ if (!a)
+ return NULL;
+
+ if (af_hint == AF_INET)
+ {
+ a->family = AF_INET;
+ a->prefix = 32;
+ a->addr.v4.s_addr = htonl(sum);
+ }
+ else
+ {
+ a->family = AF_INET6;
+ a->prefix = 128;
+
+ for (i = 0; i <= 15; i++)
+ {
+ a->addr.v6.s6_addr[15-i] = sum % 256;
+ sum >>= 8;
+ }
+ }
+
+ return a;
+ }
+
+ if (strchr(s, ':'))
+ a = cidr_parse6(s);
+ else
+ a = cidr_parse4(s);
+
+ if (!a)
+ return NULL;
+
+ if (a->family != af_hint)
+ {
+ fprintf(stderr, "attempt to '%s' %s with %s address\n",
+ op,
+ (af_hint == AF_INET) ? "ipv4" : "ipv6",
+ (af_hint != AF_INET) ? "ipv4" : "ipv6");
+ exit(4);
+ }
+
+ return a;
+}
+
+static bool cidr_howmany(struct cidr *a, struct cidr *b)
+{
+ if (!quiet)
+ {
+ if (b->prefix < a->prefix)
+ printf("0\n");
+ else
+ printf("%u\n", 1 << (b->prefix - a->prefix));
+ }
+
+ printed = true;
+
+ return true;
+}
+
+static bool cidr_quiet(struct cidr *a)
+{
+ quiet = true;
+ return true;
+}
+
+
+struct op ops[] = {
+ { .name = "add",
+ .desc = "Add argument to base address",
+ .f4.a2 = cidr_add4,
+ .f6.a2 = cidr_add6 },
+
+ { .name = "sub",
+ .desc = "Substract argument from base address",
+ .f4.a2 = cidr_sub4,
+ .f6.a2 = cidr_sub6 },
+
+ { .name = "network",
+ .desc = "Turn base address into network address",
+ .f4.a1 = cidr_network4,
+ .f6.a1 = cidr_network6 },
+
+ { .name = "broadcast",
+ .desc = "Turn base address into broadcast address",
+ .f4.a1 = cidr_broadcast4 },
+
+ { .name = "netmask",
+ .desc = "Print netmask of base address, does not change base address",
+ .f4.a1 = cidr_netmask4 },
+
+ { .name = "howmany",
+ .desc = "Print amount of righ-hand prefixes that fit into base address, "
+ "does not change base address",
+ .f4.a2 = cidr_howmany,
+ .f6.a2 = cidr_howmany },
+
+ { .name = "contains",
+ .desc = "Print '1' if argument fits into base address or '0' "
+ "if not, does not change base address",
+ .f4.a2 = cidr_contains4,
+ .f6.a2 = cidr_contains6 },
+
+ { .name = "private",
+ .desc = "Print '1' if base address is in RFC1918 private space or '0' "
+ "if not, does not change base address",
+ .f4.a1 = cidr_private4 },
+
+ { .name = "linklocal",
+ .desc = "Print '1' if base address is in 169.254.0.0/16 or FE80::/10 "
+ "link local space or '0' if not, does not change base address",
+ .f4.a1 = cidr_linklocal4,
+ .f6.a1 = cidr_linklocal6 },
+
+ { .name = "ula",
+ .desc = "Print '1' if base address is in FC00::/7 unique local address "
+ "(ULA) space or '0' if not, does not change base address",
+ .f6.a1 = cidr_ula6 },
+
+ { .name = "quiet",
+ .desc = "Suppress output, useful for test operation where the result can "
+ "be inferred from the exit code, does not change base address",
+ .f4.a1 = cidr_quiet,
+ .f6.a1 = cidr_quiet },
+
+ { .name = "print",
+ .desc = "Print intermediate result, invoked implicitely at the end of "
+ "calculation if no intermediate prints happened",
+ .f4.a1 = cidr_print4,
+ .f6.a1 = cidr_print6 },
+};
+
+static void usage(const char *prog)
+{
+ int i;
+
+ fprintf(stderr,
+ "\n"
+ "Usage:\n\n"
+ " %s {base address} operation [argument] "
+ "[operation [argument] ...]\n\n"
+ "Operations:\n\n",
+ prog);
+
+ for (i = 0; i < sizeof(ops) / sizeof(ops[0]); i++)
+ {
+ if (ops[i].f4.a2 || ops[i].f6.a2)
+ {
+ fprintf(stderr, " %s %s\n",
+ ops[i].name,
+ (ops[i].f4.a2 && ops[i].f6.a2) ? "{ipv4/ipv6/amount}" :
+ (ops[i].f6.a2 ? "{ipv6/amount}" : "{ipv4/amount}"));
+ }
+ else
+ {
+ fprintf(stderr, " %s\n", ops[i].name);
+ }
+
+ fprintf(stderr, " %s.\n", ops[i].desc);
+
+ if ((ops[i].f4.a1 && ops[i].f6.a1) || (ops[i].f4.a2 && ops[i].f6.a2))
+ fprintf(stderr, " Applicable to ipv4- and ipv6-addresses.\n\n");
+ else if (ops[i].f6.a2 || ops[i].f6.a1)
+ fprintf(stderr, " Only applicable to ipv6-addresses.\n\n");
+ else
+ fprintf(stderr, " Only applicable to ipv4-addresses.\n\n");
+ }
+
+ fprintf(stderr,
+ "Examples:\n\n"
+ " Calculate a DHCP range:\n\n"
+ " $ %s 192.168.1.1/255.255.255.0 network add 100 print add 150 print\n"
+ " 192.168.1.100\n"
+ " 192.168.1.250\n\n"
+ " Count number of prefixes:\n\n"
+ " $ %s 2001:0DB8:FDEF::/48 howmany ::/64\n"
+ " 65536\n\n",
+ prog, prog);
+
+ exit(1);
+}
+
+static bool runop(struct cidr *a, char ***arg, int *status)
+{
+ int i;
+ char *arg1 = **arg;
+ char *arg2 = *(*arg+1);
+ struct cidr *b = NULL;
+
+ if (!arg1)
+ return false;
+
+ for (i = 0; i < sizeof(ops) / sizeof(ops[0]); i++)
+ {
+ if (!strcmp(ops[i].name, arg1))
+ {
+ if (ops[i].f4.a2 || ops[i].f6.a2)
+ {
+ if (!arg2)
+ {
+ fprintf(stderr, "'%s' requires an argument\n",
+ ops[i].name);
+
+ *status = 2;
+ return false;
+ }
+
+ b = cidr_parse(ops[i].name, arg2, a->family);
+
+ if (!b)
+ {
+ fprintf(stderr, "invalid address argument for '%s'\n",
+ ops[i].name);
+
+ *status = 3;
+ return false;
+ }
+
+ *arg += 2;
+
+ if (((a->family == AF_INET) && !ops[i].f4.a2) ||
+ ((a->family == AF_INET6) && !ops[i].f6.a2))
+ {
+ fprintf(stderr, "'%s' not supported for %s addresses\n",
+ ops[i].name,
+ (a->family == AF_INET) ? "ipv4" : "ipv6");
+
+ *status = 5;
+ return false;
+ }
+
+ *status = !((a->family == AF_INET) ? ops[i].f4.a2(a, b)
+ : ops[i].f6.a2(a, b));
+
+ return true;
+ }
+ else
+ {
+ *arg += 1;
+
+ if (((a->family == AF_INET) && !ops[i].f4.a1) ||
+ ((a->family == AF_INET6) && !ops[i].f6.a1))
+ {
+ fprintf(stderr, "'%s' not supported for %s addresses\n",
+ ops[i].name,
+ (a->family == AF_INET) ? "ipv4" : "ipv6");
+
+ *status = 5;
+ return false;
+ }
+
+ *status = !((a->family == AF_INET) ? ops[i].f4.a1(a)
+ : ops[i].f6.a1(a));
+
+ return true;
+ }
+ }
+ }
+
+ return false;
+}
+
+int main(int argc, char **argv)
+{
+ int status = 0;
+ char **arg = argv+2;
+ struct cidr *a;
+
+ if (argc < 3)
+ usage(argv[0]);
+
+ a = strchr(argv[1], ':') ? cidr_parse6(argv[1]) : cidr_parse4(argv[1]);
+
+ if (!a)
+ usage(argv[0]);
+
+ while (runop(a, &arg, &status));
+
+ if (*arg)
+ {
+ fprintf(stderr, "unknown operation '%s'\n", *arg);
+ exit(6);
+ }
+
+ if (!printed && (status < 2))
+ {
+ if (a->family == AF_INET)
+ cidr_print4(a);
+ else
+ cidr_print6(a);
+ }
+
+ exit(status);
+}
projects / openwrt / openwrt.git / commitdiff