/* $OpenBSD: addr.c,v 1.4 2021/10/22 10:51:57 dtucker Exp $ */ /* * Copyright (c) 2004-2008 Damien Miller * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #include #include #include #include #include #include #include #include #include "addr.h" #define _SA(x) ((struct sockaddr *)(x)) int addr_unicast_masklen(int af) { switch (af) { case AF_INET: return 32; case AF_INET6: return 128; default: return -1; } } static inline int masklen_valid(int af, u_int masklen) { switch (af) { case AF_INET: return masklen <= 32 ? 0 : -1; case AF_INET6: return masklen <= 128 ? 0 : -1; default: return -1; } } int addr_xaddr_to_sa(const struct xaddr *xa, struct sockaddr *sa, socklen_t *len, u_int16_t port) { struct sockaddr_in *in4 = (struct sockaddr_in *)sa; struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)sa; if (xa == NULL || sa == NULL || len == NULL) return -1; switch (xa->af) { case AF_INET: if (*len < sizeof(*in4)) return -1; memset(sa, '\0', sizeof(*in4)); *len = sizeof(*in4); #ifdef SOCK_HAS_LEN in4->sin_len = sizeof(*in4); #endif in4->sin_family = AF_INET; in4->sin_port = htons(port); memcpy(&in4->sin_addr, &xa->v4, sizeof(in4->sin_addr)); break; case AF_INET6: if (*len < sizeof(*in6)) return -1; memset(sa, '\0', sizeof(*in6)); *len = sizeof(*in6); #ifdef SOCK_HAS_LEN in6->sin6_len = sizeof(*in6); #endif in6->sin6_family = AF_INET6; in6->sin6_port = htons(port); memcpy(&in6->sin6_addr, &xa->v6, sizeof(in6->sin6_addr)); in6->sin6_scope_id = xa->scope_id; break; default: return -1; } return 0; } /* * Convert struct sockaddr to struct xaddr * Returns 0 on success, -1 on failure. */ int addr_sa_to_xaddr(struct sockaddr *sa, socklen_t slen, struct xaddr *xa) { struct sockaddr_in *in4 = (struct sockaddr_in *)sa; struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)sa; memset(xa, '\0', sizeof(*xa)); switch (sa->sa_family) { case AF_INET: if (slen < (socklen_t)sizeof(*in4)) return -1; xa->af = AF_INET; memcpy(&xa->v4, &in4->sin_addr, sizeof(xa->v4)); break; case AF_INET6: if (slen < (socklen_t)sizeof(*in6)) return -1; xa->af = AF_INET6; memcpy(&xa->v6, &in6->sin6_addr, sizeof(xa->v6)); #ifdef HAVE_STRUCT_SOCKADDR_IN6_SIN6_SCOPE_ID xa->scope_id = in6->sin6_scope_id; #endif break; default: return -1; } return 0; } int addr_invert(struct xaddr *n) { int i; if (n == NULL) return -1; switch (n->af) { case AF_INET: n->v4.s_addr = ~n->v4.s_addr; return 0; case AF_INET6: for (i = 0; i < 4; i++) n->addr32[i] = ~n->addr32[i]; return 0; default: return -1; } } /* * Calculate a netmask of length 'l' for address family 'af' and * store it in 'n'. * Returns 0 on success, -1 on failure. */ int addr_netmask(int af, u_int l, struct xaddr *n) { int i; if (masklen_valid(af, l) != 0 || n == NULL) return -1; memset(n, '\0', sizeof(*n)); switch (af) { case AF_INET: n->af = AF_INET; if (l == 0) return 0; n->v4.s_addr = htonl((0xffffffff << (32 - l)) & 0xffffffff); return 0; case AF_INET6: n->af = AF_INET6; for (i = 0; i < 4 && l >= 32; i++, l -= 32) n->addr32[i] = 0xffffffffU; if (i < 4 && l != 0) n->addr32[i] = htonl((0xffffffff << (32 - l)) & 0xffffffff); return 0; default: return -1; } } int addr_hostmask(int af, u_int l, struct xaddr *n) { if (addr_netmask(af, l, n) == -1 || addr_invert(n) == -1) return -1; return 0; } /* * Perform logical AND of addresses 'a' and 'b', storing result in 'dst'. * Returns 0 on success, -1 on failure. */ int addr_and(struct xaddr *dst, const struct xaddr *a, const struct xaddr *b) { int i; if (dst == NULL || a == NULL || b == NULL || a->af != b->af) return -1; memcpy(dst, a, sizeof(*dst)); switch (a->af) { case AF_INET: dst->v4.s_addr &= b->v4.s_addr; return 0; case AF_INET6: dst->scope_id = a->scope_id; for (i = 0; i < 4; i++) dst->addr32[i] &= b->addr32[i]; return 0; default: return -1; } } int addr_cmp(const struct xaddr *a, const struct xaddr *b) { int i; if (a->af != b->af) return (a->af == AF_INET6 ? 1 : -1); switch (a->af) { case AF_INET: /* * Can't just subtract here as 255.255.255.255 - 0.0.0.0 is * too big to fit into a signed int */ if (a->v4.s_addr == b->v4.s_addr) return 0; return (ntohl(a->v4.s_addr) > ntohl(b->v4.s_addr) ? 1 : -1); case AF_INET6: /* * Do this a byte at a time to avoid the above issue and * any endian problems */ for (i = 0; i < 16; i++) if (a->addr8[i] - b->addr8[i] != 0) return (a->addr8[i] - b->addr8[i]); if (a->scope_id == b->scope_id) return (0); return (a->scope_id > b->scope_id ? 1 : -1); default: return (-1); } } int addr_is_all0s(const struct xaddr *a) { int i; switch (a->af) { case AF_INET: return (a->v4.s_addr == 0 ? 0 : -1); case AF_INET6: for (i = 0; i < 4; i++) if (a->addr32[i] != 0) return -1; return 0; default: return -1; } } /* * Test whether host portion of address 'a', as determined by 'masklen' * is all zeros. * Returns 0 if host portion of address is all-zeros, * -1 if not all zeros or on failure. */ int addr_host_is_all0s(const struct xaddr *a, u_int masklen) { struct xaddr tmp_addr, tmp_mask, tmp_result; memcpy(&tmp_addr, a, sizeof(tmp_addr)); if (addr_hostmask(a->af, masklen, &tmp_mask) == -1) return -1; if (addr_and(&tmp_result, &tmp_addr, &tmp_mask) == -1) return -1; return addr_is_all0s(&tmp_result); } /* * Parse string address 'p' into 'n'. * Returns 0 on success, -1 on failure. */ int addr_pton(const char *p, struct xaddr *n) { struct addrinfo hints, *ai; memset(&hints, '\0', sizeof(hints)); hints.ai_flags = AI_NUMERICHOST; if (p == NULL || getaddrinfo(p, NULL, &hints, &ai) != 0) return -1; if (ai == NULL) return -1; if (ai->ai_addr == NULL) { freeaddrinfo(ai); return -1; } if (n != NULL && addr_sa_to_xaddr(ai->ai_addr, ai->ai_addrlen, n) == -1) { freeaddrinfo(ai); return -1; } freeaddrinfo(ai); return 0; } int addr_sa_pton(const char *h, const char *s, struct sockaddr *sa, socklen_t slen) { struct addrinfo hints, *ai; memset(&hints, '\0', sizeof(hints)); hints.ai_flags = AI_NUMERICHOST; if (h == NULL || getaddrinfo(h, s, &hints, &ai) != 0) return -1; if (ai == NULL) return -1; if (ai->ai_addr == NULL) { freeaddrinfo(ai); return -1; } if (sa != NULL) { if (slen < ai->ai_addrlen) { freeaddrinfo(ai); return -1; } memcpy(sa, &ai->ai_addr, ai->ai_addrlen); } freeaddrinfo(ai); return 0; } int addr_ntop(const struct xaddr *n, char *p, size_t len) { struct sockaddr_storage ss; socklen_t slen = sizeof(ss); if (addr_xaddr_to_sa(n, _SA(&ss), &slen, 0) == -1) return -1; if (p == NULL || len == 0) return -1; if (getnameinfo(_SA(&ss), slen, p, len, NULL, 0, NI_NUMERICHOST) == -1) return -1; return 0; } /* * Parse a CIDR address (x.x.x.x/y or xxxx:yyyy::/z). * Return -1 on parse error, -2 on inconsistency or 0 on success. */ int addr_pton_cidr(const char *p, struct xaddr *n, u_int *l) { struct xaddr tmp; long unsigned int masklen = 999; char addrbuf[64], *mp, *cp; /* Don't modify argument */ if (p == NULL || strlcpy(addrbuf, p, sizeof(addrbuf)) >= sizeof(addrbuf)) return -1; if ((mp = strchr(addrbuf, '/')) != NULL) { *mp = '\0'; mp++; masklen = strtoul(mp, &cp, 10); if (*mp == '\0' || *cp != '\0' || masklen > 128) return -1; } if (addr_pton(addrbuf, &tmp) == -1) return -1; if (mp == NULL) masklen = addr_unicast_masklen(tmp.af); if (masklen_valid(tmp.af, masklen) == -1) return -2; if (addr_host_is_all0s(&tmp, masklen) != 0) return -2; if (n != NULL) memcpy(n, &tmp, sizeof(*n)); if (l != NULL) *l = masklen; return 0; } int addr_netmatch(const struct xaddr *host, const struct xaddr *net, u_int masklen) { struct xaddr tmp_mask, tmp_result; if (host->af != net->af) return -1; if (addr_netmask(host->af, masklen, &tmp_mask) == -1) return -1; if (addr_and(&tmp_result, host, &tmp_mask) == -1) return -1; return addr_cmp(&tmp_result, net); }