X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=adns.git;a=blobdiff_plain;f=src%2Faddrfam.c;fp=src%2Faddrfam.c;h=f606612bdf9e5fb1f8b49838968560e4dc3c12b9;hp=0000000000000000000000000000000000000000;hb=07554ccd8286775b4f88a608ba3b94ff7b9efaf9;hpb=f930c455a13d7d30ee94bdbfc460bc6227cda111 diff --git a/src/addrfam.c b/src/addrfam.c new file mode 100644 index 0000000..f606612 --- /dev/null +++ b/src/addrfam.c @@ -0,0 +1,212 @@ +/* + * addrfam.c + * - address-family specific code + */ +/* + * This file is part of adns, which is + * Copyright (C) 1997-2000,2003,2006 Ian Jackson + * Copyright (C) 1999-2000,2003,2006 Tony Finch + * Copyright (C) 1991 Massachusetts Institute of Technology + * (See the file INSTALL for full details.) + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2, or (at your option) + * any later version. + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software Foundation, + * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ + +#include +#include +#include +#include + +#include +#include +#include +#include + +#include "internal.h" + +/* + * General address-family operations. + */ + +#define SIN(sa) ((struct sockaddr_in *)(sa)) +#define CSIN(sa) ((const struct sockaddr_in *)(sa)) + +#define SIN6(sa) ((struct sockaddr_in6 *)(sa)) +#define CSIN6(sa) ((const struct sockaddr_in6 *)(sa)) + +/* This gadget (thanks, Richard Kettlewell) makes sure that we handle the + * same set of address families in each switch. */ +#define AF_CASES(pre) \ + case AF_INET: goto pre##_inet; \ + case AF_INET6: goto pre##_inet6 + +static void unknown_af(int af) { + fprintf(stderr, "ADNS INTERNAL: unknown address family %d\n", af); + abort(); +} + +#define IN6_ADDR_EQUALP(a, b) \ + (!memcmp((a).s6_addr, (b).s6_addr, sizeof((a).s6_addr))) + +int adns__genaddr_equal_p(int af, const union gen_addr *a, + int bf, const void *b) { + const union gen_addr *bb= b; + if (af != bf) return 0; + switch (af) { + AF_CASES(af); + af_inet: return a->v4.s_addr == bb->v4.s_addr; + af_inet6: return IN6_ADDR_EQUALP(a->v6, bb->v6); + default: unknown_af(af); return -1; + } +} + +int adns__sockaddr_equal_p(const struct sockaddr *sa, + const struct sockaddr *sb) { + if (sa->sa_family != sb->sa_family) return 0; + switch (sa->sa_family) { + AF_CASES(af); + af_inet: { + const struct sockaddr_in *sina= CSIN(sa), *sinb= CSIN(sb); + return (sina->sin_addr.s_addr == sinb->sin_addr.s_addr && + sina->sin_port == sinb->sin_port); + } + af_inet6: { + /* Don't check the flowlabel. That's apparently useful for routing + * performance, but doesn't affect the address in any important + * respect. */ + const struct sockaddr_in6 *sin6a= CSIN6(sa), *sin6b= CSIN6(sb); + return (IN6_ADDR_EQUALP(sin6a->sin6_addr, sin6b->sin6_addr) && + sin6a->sin6_port == sin6b->sin6_port && + sin6a->sin6_scope_id == sin6b->sin6_scope_id); + } + default: + unknown_af(sa->sa_family); + return -1; + } +} + +int adns__addr_width(int af) { + switch (af) { + AF_CASES(af); + af_inet: return 32; + af_inet6: return 128; + default: unknown_af(af); return -1; + } +} + +void adns__prefix_mask(int af, int len, union gen_addr *mask_r) { + switch (af) { + AF_CASES(af); + af_inet: + assert(len <= 32); + mask_r->v4.s_addr= htonl(!len ? 0 : 0xffffffff << (32-len)); + break; + af_inet6: { + int i= len/8, j= len%8; + unsigned char *m= mask_r->v6.s6_addr; + assert(len <= 128); + memset(m, 0xff, i); + if (j) m[i++]= (0xff << (8-j)) & 0xff; + memset(m+i, 0, 16-i); + } break; + default: + unknown_af(af); + break; + } +} + +int adns__guess_prefix_length(int af, const union gen_addr *addr) { + switch (af) { + AF_CASES(af); + af_inet: { + unsigned a= (ntohl(addr->v4.s_addr) >> 24) & 0xff; + if (a < 128) return 8; + else if (a < 192) return 16; + else if (a < 224) return 24; + else return -1; + } break; + af_inet6: + return 64; + default: + unknown_af(af); + return -1; + } +} + +int adns__addr_match_p(int addraf, const union gen_addr *addr, + int netaf, const union gen_addr *base, + const union gen_addr *mask) +{ + if (addraf != netaf) return 0; + switch (addraf) { + AF_CASES(af); + af_inet: + return (addr->v4.s_addr & mask->v4.s_addr) == base->v4.s_addr; + af_inet6: { + int i; + const char *a= addr->v6.s6_addr; + const char *b= base->v6.s6_addr; + const char *m= mask->v6.s6_addr; + for (i = 0; i < 16; i++) + if ((a[i] & m[i]) != b[i]) return 0; + return 1; + } break; + default: + unknown_af(addraf); + return -1; + } +} + +void adns__sockaddr_extract(const struct sockaddr *sa, + union gen_addr *a_r, int *port_r) { + switch (sa->sa_family) { + AF_CASES(af); + af_inet: { + const struct sockaddr_in *sin = CSIN(sa); + if (port_r) *port_r= ntohs(sin->sin_port); + if (a_r) a_r->v4= sin->sin_addr; + break; + } + af_inet6: { + const struct sockaddr_in6 *sin6 = CSIN6(sa); + if (port_r) *port_r= ntohs(sin6->sin6_port); + if (a_r) a_r->v6= sin6->sin6_addr; + break; + } + default: + unknown_af(sa->sa_family); + } +} + +void adns__sockaddr_inject(const union gen_addr *a, int port, + struct sockaddr *sa) { + switch (sa->sa_family) { + AF_CASES(af); + af_inet: { + struct sockaddr_in *sin = SIN(sa); + if (port != -1) sin->sin_port= htons(port); + if (a) sin->sin_addr= a->v4; + break; + } + af_inet6: { + struct sockaddr_in6 *sin6 = SIN6(sa); + if (port != -1) sin6->sin6_port= htons(port); + if (a) sin6->sin6_addr= a->v6; + break; + } + default: + unknown_af(sa->sa_family); + } +}