text: /*
   * mapcalc - MAP parameter calculation
   *
   * Author: Steven Barth <cyrus@openwrt.org>
   * Copyright (c) 2014-2015 cisco Systems, Inc.
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2
   * as published by the Free Software Foundation
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   */
  
  #include <stdlib.h>
  #include <stdio.h>
  #include <arpa/inet.h>
  #include <errno.h>
  #include <libubus.h>
  #include <libubox/utils.h>
  
  
  struct blob_attr *dump = NULL;
  
  enum {
  	DUMP_ATTR_INTERFACE,
  	DUMP_ATTR_MAX
  };
  
  static const struct blobmsg_policy dump_attrs[DUMP_ATTR_MAX] = {
  	[DUMP_ATTR_INTERFACE] = { .name = "interface", .type = BLOBMSG_TYPE_ARRAY },
  };
  
  
  enum {
  	IFACE_ATTR_INTERFACE,
  	IFACE_ATTR_PREFIX,
  	IFACE_ATTR_ADDRESS,
  	IFACE_ATTR_MAX,
  };
  
  static const struct blobmsg_policy iface_attrs[IFACE_ATTR_MAX] = {
  	[IFACE_ATTR_INTERFACE] = { .name = "interface", .type = BLOBMSG_TYPE_STRING },
  	[IFACE_ATTR_PREFIX] = { .name = "ipv6-prefix", .type = BLOBMSG_TYPE_ARRAY },
  	[IFACE_ATTR_ADDRESS] = { .name = "ipv6-address", .type = BLOBMSG_TYPE_ARRAY },
  };
  
  
  enum {
  	PREFIX_ATTR_ADDRESS,
  	PREFIX_ATTR_MASK,
  	PREFIX_ATTR_MAX,
  };
  
  static const struct blobmsg_policy prefix_attrs[PREFIX_ATTR_MAX] = {
  	[PREFIX_ATTR_ADDRESS] = { .name = "address", .type = BLOBMSG_TYPE_STRING },
  	[PREFIX_ATTR_MASK] = { .name = "mask", .type = BLOBMSG_TYPE_INT32 },
  };
  
  static int bmemcmp(const void *av, const void *bv, size_t bits)
  {
  	const uint8_t *a = av, *b = bv;
  	size_t bytes = bits / 8;
  	bits %= 8;
  
  	int res = memcmp(a, b, bytes);
  	if (res == 0 && bits > 0)
  		res = (a[bytes] >> (8 - bits)) - (b[bytes] >> (8 - bits));
  
  	return res;
  }
  
  static void bmemcpy(void *av, const void *bv, size_t bits)
  {
  	uint8_t *a = av;
  	const uint8_t *b = bv;
  
  	size_t bytes = bits / 8;
  	bits %= 8;
  	memcpy(a, b, bytes);
  
  	if (bits > 0) {
  		uint8_t mask = (1 << (8 - bits)) - 1;
  		a[bytes] = (a[bytes] & mask) | ((~mask) & b[bytes]);
  	}
  }
  
  static void bmemcpys64(void *av, const void *bv, size_t frombits, size_t nbits)
  {
  	uint64_t buf = 0;
  	const uint8_t *b = bv;
  	size_t frombyte = frombits / 8, tobyte = (frombits + nbits) / 8;
  
  	memcpy(&buf, &b[frombyte], tobyte - frombyte + 1);
  	buf = cpu_to_be64(be64_to_cpu(buf) << (frombits % 8));
  
  	bmemcpy(av, &buf, nbits);
  }
  
  static void handle_dump(struct ubus_request *req __attribute__((unused)),
  		int type __attribute__((unused)), struct blob_attr *msg)
  {
  	struct blob_attr *tb[DUMP_ATTR_INTERFACE];
  	blobmsg_parse(dump_attrs, DUMP_ATTR_MAX, tb, blob_data(msg), blob_len(msg));
  
  	if (!tb[DUMP_ATTR_INTERFACE])
  		return;
  
  	dump = blob_memdup(tb[DUMP_ATTR_INTERFACE]);
  }
  
  static void match_prefix(int *pdlen, struct in6_addr *pd, struct blob_attr *cur,
  		const struct in6_addr *ipv6prefix, int prefix6len)
  {
  	struct blob_attr *d;
  	unsigned drem;
  
  	if (!cur || blobmsg_type(cur) != BLOBMSG_TYPE_ARRAY || !blobmsg_check_attr(cur, NULL))
  		return;
  
  	blobmsg_for_each_attr(d, cur, drem) {
  		struct blob_attr *ptb[PREFIX_ATTR_MAX];
  		blobmsg_parse(prefix_attrs, PREFIX_ATTR_MAX, ptb,
  				blobmsg_data(d), blobmsg_data_len(d));
  
  		if (!ptb[PREFIX_ATTR_ADDRESS] || !ptb[PREFIX_ATTR_MASK])
  			continue;
  
  		struct in6_addr prefix = IN6ADDR_ANY_INIT;
  		int mask = blobmsg_get_u32(ptb[PREFIX_ATTR_MASK]);
  		inet_pton(AF_INET6, blobmsg_get_string(ptb[PREFIX_ATTR_ADDRESS]), &prefix);
  
  		// lw4over6 /128-address-as-PD matching madness workaround
  		if (mask == 128)
  			mask = 64;
  
  		if (*pdlen < mask && mask >= prefix6len &&
  				!bmemcmp(&prefix, ipv6prefix, prefix6len)) {
  			bmemcpy(pd, &prefix, mask);
  			*pdlen = mask;
  		}
  	}
  }
  
  enum {
  	OPT_TYPE,
  	OPT_FMR,
  	OPT_EALEN,
  	OPT_PREFIX4LEN,
  	OPT_PREFIX6LEN,
  	OPT_IPV6PREFIX,
  	OPT_IPV4PREFIX,
  	OPT_OFFSET,
  	OPT_PSIDLEN,
  	OPT_PSID,
  	OPT_BR,
  	OPT_DMR,
  	OPT_MAX
  };
  
  static char *const token[] = {
  	[OPT_TYPE] = "type",
  	[OPT_FMR] = "fmr",
  	[OPT_EALEN] = "ealen",
  	[OPT_PREFIX4LEN] = "prefix4len",
  	[OPT_PREFIX6LEN] = "prefix6len",
  	[OPT_IPV6PREFIX] = "ipv6prefix",
  	[OPT_IPV4PREFIX] = "ipv4prefix",
  	[OPT_OFFSET] = "offset",
  	[OPT_PSIDLEN] = "psidlen",
  	[OPT_PSID] = "psid",
  	[OPT_BR] = "br",
  	[OPT_DMR] = "dmr",
  	[OPT_MAX] = NULL
  };
  
  
  int main(int argc, char *argv[])
  {
  	int status = 0;
  	const char *iface = argv[1];
  
  	const char *legacy_env = getenv("LEGACY");
  	bool legacy = legacy_env && atoi(legacy_env);
  
  
  	if (argc < 3) {
  		fprintf(stderr, "Usage: %s <interface|*> <rule1> [rule2] [...]\n", argv[0]);
  		return 1;
  	}
  
  	uint32_t network_interface;
  	struct ubus_context *ubus = ubus_connect(NULL);
  	if (ubus) {
  		ubus_lookup_id(ubus, "network.interface", &network_interface);
  		ubus_invoke(ubus, network_interface, "dump", NULL, handle_dump, NULL, 5000);
  	}
  
  	int rulecnt = 0;
  	for (int i = 2; i < argc; ++i) {
  		bool lw4o6 = false;
  		bool fmr = false;
  		int ealen = -1;
  		int addr4len = 32;
  		int prefix4len = 32;
  		int prefix6len = -1;
  		int pdlen = -1;
  		struct in_addr ipv4prefix = {INADDR_ANY};
  		struct in_addr ipv4addr = {INADDR_ANY};
  		struct in6_addr ipv6addr = IN6ADDR_ANY_INIT;
  		struct in6_addr ipv6prefix = IN6ADDR_ANY_INIT;
  		struct in6_addr pd = IN6ADDR_ANY_INIT;
  		int offset = -1;
  		int psidlen = -1;
  		int psid = -1;
  		uint16_t psid16 = 0;
  		const char *dmr = NULL;
  		const char *br = NULL;
  
  		for (char *rule = strdup(argv[i]); *rule; ) {
  			char *value;
  			int intval;
  			int idx = getsubopt(&rule, token, &value);
  			errno = 0;
  
  			if (idx == OPT_TYPE) {
  				lw4o6 = (value && !strcmp(value, "lw4o6"));
  			} else if (idx == OPT_FMR) {
  				fmr = true;
  			} else if (idx == OPT_EALEN && (intval = strtoul(value, NULL, 0)) <= 48 && !errno) {
  				ealen = intval;
  			} else if (idx == OPT_PREFIX4LEN && (intval = strtoul(value, NULL, 0)) <= 32 && !errno) {
  				prefix4len = intval;
  			} else if (idx == OPT_PREFIX6LEN && (intval = strtoul(value, NULL, 0)) <= 112 && !errno) {
  				prefix6len = intval;
  			} else if (idx == OPT_IPV4PREFIX && inet_pton(AF_INET, value, &ipv4prefix) == 1) {
  				// dummy
  			} else if (idx == OPT_IPV6PREFIX && inet_pton(AF_INET6, value, &ipv6prefix) == 1) {
  				// dummy
  			} else if (idx == OPT_OFFSET && (intval = strtoul(value, NULL, 0)) <= 16 && !errno) {
  				offset = intval;
  			} else if (idx == OPT_PSIDLEN && (intval = strtoul(value, NULL, 0)) <= 16 && !errno) {
  				psidlen = intval;
  			} else if (idx == OPT_PSID && (intval = strtoul(value, NULL, 0)) <= 65535 && !errno) {
  				psid = intval;
  			} else if (idx == OPT_DMR) {
  				dmr = value;
  			} else if (idx == OPT_BR) {
  				br = value;
  			} else {
  				if (idx == -1 || idx >= OPT_MAX)
  					fprintf(stderr, "Skipped invalid option: %s\n", value);
  				else
  					fprintf(stderr, "Skipped invalid value %s for option %s\n",
  							value, token[idx]);
  			}
  		}
  
  		if (offset < 0)
  			offset = (lw4o6) ? 0 : (legacy) ? 4 : 6;
  
  		// LW4over6 doesn't have an EALEN and has no psid-autodetect
  		if (lw4o6) {
  			if (psidlen < 0)
  				psidlen = 0;
  
  			ealen = psidlen;
  		}
  
  		// Find PD
  		struct blob_attr *c;
  		unsigned rem;
  		blobmsg_for_each_attr(c, dump, rem) {
  			struct blob_attr *tb[IFACE_ATTR_MAX];
  			blobmsg_parse(iface_attrs, IFACE_ATTR_MAX, tb, blobmsg_data(c), blobmsg_data_len(c));
  
  			if (!tb[IFACE_ATTR_INTERFACE] || (strcmp(argv[1], "*") && strcmp(argv[1],
  					blobmsg_get_string(tb[IFACE_ATTR_INTERFACE]))))
  				continue;
  
  			match_prefix(&pdlen, &pd, tb[IFACE_ATTR_PREFIX], &ipv6prefix, prefix6len);
  
  			if (lw4o6)
  				match_prefix(&pdlen, &pd, tb[IFACE_ATTR_ADDRESS], &ipv6prefix, prefix6len);
  
  			if (pdlen >= 0) {
  				iface = blobmsg_get_string(tb[IFACE_ATTR_INTERFACE]);
  				break;
  			}
  		}
  
  		if (ealen < 0 && pdlen >= 0)
  			ealen = pdlen - prefix6len;
  
  		if (psidlen <= 0) {
  			psidlen = ealen - (32 - prefix4len);
  			psid = -1;
  		}
  
  		if (psid < 0 && psidlen <= 16 && psidlen >= 0 && pdlen >= 0 && ealen >= psidlen) {
  			bmemcpys64(&psid16, &pd, prefix6len + ealen - psidlen, psidlen);
  			psid = be16_to_cpu(psid16);
  		}
  
  		psid16 = cpu_to_be16(psid >> (16 - psidlen));
  
  		if (prefix4len < 0 || prefix6len < 0 || ealen < 0 || ealen < psidlen) {
  			fprintf(stderr, "Skipping invalid or incomplete rule: %s\n", argv[i]);
  			status = 1;
  			continue;
  		}
  
  		if ((pdlen >= 0 || ealen == psidlen) && ealen >= psidlen) {
  			bmemcpys64(&ipv4addr, &pd, prefix6len, ealen - psidlen);
  			ipv4addr.s_addr = htonl(ntohl(ipv4addr.s_addr) >> prefix4len);
  			bmemcpy(&ipv4addr, &ipv4prefix, prefix4len);
  
  			if (prefix4len + ealen < 32)
  				addr4len = prefix4len + ealen;
  		}
  
  		if (pdlen < 0 && !fmr) {
  			fprintf(stderr, "Skipping non-FMR without matching PD: %s\n", argv[i]);
  			status = 1;
  			continue;
  		} else if (pdlen >= 0) {
  			size_t v4offset = (legacy) ? 9 : 10;
  			memcpy(&ipv6addr.s6_addr[v4offset], &ipv4addr, 4);
  			memcpy(&ipv6addr.s6_addr[v4offset + 4], &psid16, 2);
  			bmemcpy(&ipv6addr, &pd, pdlen);
  		}
  
  		++rulecnt;
  		char ipv4addrbuf[INET_ADDRSTRLEN];
  		char ipv4prefixbuf[INET_ADDRSTRLEN];
  		char ipv6prefixbuf[INET6_ADDRSTRLEN];
  		char ipv6addrbuf[INET6_ADDRSTRLEN];
  		char pdbuf[INET6_ADDRSTRLEN];
  
  		inet_ntop(AF_INET, &ipv4addr, ipv4addrbuf, sizeof(ipv4addrbuf));
  		inet_ntop(AF_INET, &ipv4prefix, ipv4prefixbuf, sizeof(ipv4prefixbuf));
  		inet_ntop(AF_INET6, &ipv6prefix, ipv6prefixbuf, sizeof(ipv6prefixbuf));
  		inet_ntop(AF_INET6, &ipv6addr, ipv6addrbuf, sizeof(ipv6addrbuf));
  		inet_ntop(AF_INET6, &pd, pdbuf, sizeof(pdbuf));
  
  		printf("RULE_%d_FMR=%d\n", rulecnt, fmr);
  		printf("RULE_%d_EALEN=%d\n", rulecnt, ealen);
  		printf("RULE_%d_PSIDLEN=%d\n", rulecnt, psidlen);
  		printf("RULE_%d_OFFSET=%d\n", rulecnt, offset);
  		printf("RULE_%d_PREFIX4LEN=%d\n", rulecnt, prefix4len);
  		printf("RULE_%d_PREFIX6LEN=%d\n", rulecnt, prefix6len);
  		printf("RULE_%d_IPV4PREFIX=%s\n", rulecnt, ipv4prefixbuf);
  		printf("RULE_%d_IPV6PREFIX=%s\n", rulecnt, ipv6prefixbuf);
  
  		if (pdlen >= 0) {
  			printf("RULE_%d_IPV6PD=%s\n", rulecnt, pdbuf);
  			printf("RULE_%d_PD6LEN=%d\n", rulecnt, pdlen);
  			printf("RULE_%d_PD6IFACE=%s\n", rulecnt, iface);
  			printf("RULE_%d_IPV6ADDR=%s\n", rulecnt, ipv6addrbuf);
  			printf("RULE_BMR=%d\n", rulecnt);
  		}
  
  		if (ipv4addr.s_addr) {
  			printf("RULE_%d_IPV4ADDR=%s\n", rulecnt, ipv4addrbuf);
  			printf("RULE_%d_ADDR4LEN=%d\n", rulecnt, addr4len);
  		}
  
  
  		if (psidlen > 0 && psid >= 0) {
  			printf("RULE_%d_PORTSETS='", rulecnt);
  			for (int k = (offset) ? 1 : 0; k < (1 << offset); ++k) {
  				int start = (k << (16 - offset)) | (psid >> offset);
  				int end = start + (1 << (16 - offset - psidlen)) - 1;
  
  				if (start == 0)
  					start = 1;
  
  				if (start <= end)
  					printf("%d-%d ", start, end);
  			}
  			printf("'\n");
  		}
  
  		if (dmr)
  			printf("RULE_%d_DMR=%s\n", rulecnt, dmr);
  
  		if (br)
  			printf("RULE_%d_BR=%s\n", rulecnt, br);
  	}
  
  	printf("RULE_COUNT=%d\n", rulecnt);
  	return status;
  }
  