| /* $NetBSD: res_init.c,v 1.8 2006/03/19 03:10:08 christos Exp $ */ |
| |
| /* |
| * Copyright (c) 1985, 1989, 1993 |
| * The Regents of the University of California. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * 3. All advertising materials mentioning features or use of this software |
| * must display the following acknowledgement: |
| * This product includes software developed by the University of |
| * California, Berkeley and its contributors. |
| * 4. Neither the name of the University nor the names of its contributors |
| * may be used to endorse or promote products derived from this software |
| * without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| */ |
| |
| /* |
| * Portions Copyright (c) 1993 by Digital Equipment Corporation. |
| * |
| * 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, and that |
| * the name of Digital Equipment Corporation not be used in advertising or |
| * publicity pertaining to distribution of the document or software without |
| * specific, written prior permission. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL |
| * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT |
| * CORPORATION 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. |
| */ |
| |
| /* |
| * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") |
| * Portions Copyright (c) 1996-1999 by Internet Software Consortium. |
| * |
| * 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 ISC DISCLAIMS ALL WARRANTIES |
| * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
| * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC 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. |
| */ |
| |
| #define LOG_TAG "resolv" |
| |
| #include <sys/param.h> |
| #include <sys/socket.h> |
| #include <sys/time.h> |
| #include <sys/types.h> |
| |
| #include <arpa/inet.h> |
| #include <arpa/nameser.h> |
| #include <netinet/in.h> |
| |
| #include <android-base/logging.h> |
| #include <ctype.h> |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <netdb.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <unistd.h> |
| |
| #include "netd_resolv/resolv.h" |
| #include "res_state_ext.h" |
| #include "resolv_private.h" |
| |
| /* |
| * Resolver state default settings. |
| */ |
| |
| /* |
| * Set up default settings. If the configuration file exist, the values |
| * there will have precedence. Otherwise, the server address is set to |
| * INADDR_ANY and the default domain name comes from the gethostname(). |
| * |
| * An interrim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1 |
| * rather than INADDR_ANY ("0.0.0.0") as the default name server address |
| * since it was noted that INADDR_ANY actually meant ``the first interface |
| * you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface, |
| * it had to be "up" in order for you to reach your own name server. It |
| * was later decided that since the recommended practice is to always |
| * install local static routes through 127.0.0.1 for all your network |
| * interfaces, that we could solve this problem without a code change. |
| * |
| * The configuration file should always be used, since it is the only way |
| * to specify a default domain. If you are running a server on your local |
| * machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1" |
| * in the configuration file. |
| * |
| * Return 0 if completes successfully, -1 on error |
| */ |
| int res_ninit(res_state statp) { |
| return res_vinit(statp, 0); |
| } |
| |
| /* This function has to be reachable by res_data.c but not publicly. */ |
| int res_vinit(res_state statp, int preinit) { |
| char *cp, **pp; |
| char buf[BUFSIZ]; |
| int nserv = 0; /* number of nameserver records read from file */ |
| int havesearch = 0; |
| int dots; |
| sockaddr_union u[2]; |
| |
| if ((statp->options & RES_INIT) != 0U) res_ndestroy(statp); |
| |
| if (!preinit) { |
| statp->netid = NETID_UNSET; |
| statp->options = RES_DEFAULT; |
| statp->id = arc4random_uniform(65536); |
| statp->_mark = MARK_UNSET; |
| } |
| |
| memset(u, 0, sizeof(u)); |
| u[nserv].sin.sin_addr.s_addr = INADDR_ANY; |
| u[nserv].sin.sin_family = AF_INET; |
| u[nserv].sin.sin_port = htons(NAMESERVER_PORT); |
| nserv++; |
| statp->nscount = 0; |
| statp->ndots = 1; |
| statp->_vcsock = -1; |
| statp->_flags = 0; |
| statp->_u._ext.nscount = 0; |
| statp->_u._ext.ext = (res_state_ext*) malloc(sizeof(*statp->_u._ext.ext)); |
| statp->use_local_nameserver = false; |
| if (statp->_u._ext.ext != NULL) { |
| memset(statp->_u._ext.ext, 0, sizeof(*statp->_u._ext.ext)); |
| statp->_u._ext.ext->nsaddrs[0].sin = statp->nsaddr; |
| strcpy(statp->_u._ext.ext->nsuffix, "ip6.arpa"); |
| strcpy(statp->_u._ext.ext->nsuffix2, "ip6.int"); |
| } |
| statp->nsort = 0; |
| res_setservers(statp, u, nserv); |
| |
| if (statp->defdname[0] == 0 && gethostname(buf, sizeof(statp->defdname) - 1) == 0 && |
| (cp = strchr(buf, '.')) != NULL) |
| strcpy(statp->defdname, cp + 1); |
| |
| /* find components of local domain that might be searched */ |
| if (havesearch == 0) { |
| pp = statp->dnsrch; |
| *pp++ = statp->defdname; |
| *pp = NULL; |
| |
| dots = 0; |
| for (cp = statp->defdname; *cp; cp++) dots += (*cp == '.'); |
| |
| cp = statp->defdname; |
| while (pp < statp->dnsrch + MAXDFLSRCH) { |
| if (dots < LOCALDOMAINPARTS) break; |
| cp = strchr(cp, '.') + 1; /* we know there is one */ |
| *pp++ = cp; |
| dots--; |
| } |
| *pp = NULL; |
| LOG(DEBUG) << __func__ << ": dnsrch list:"; |
| for (pp = statp->dnsrch; *pp; pp++) LOG(DEBUG) << "\t" << *pp; |
| } |
| |
| if (nserv > 0) { |
| statp->nscount = nserv; |
| statp->options |= RES_INIT; |
| } |
| return (0); |
| } |
| |
| |
| /* |
| * This routine is for closing the socket if a virtual circuit is used and |
| * the program wants to close it. This provides support for endhostent() |
| * which expects to close the socket. |
| * |
| * This routine is not expected to be user visible. |
| */ |
| void res_nclose(res_state statp) { |
| int ns; |
| |
| if (statp->_vcsock >= 0) { |
| (void) close(statp->_vcsock); |
| statp->_vcsock = -1; |
| statp->_flags &= ~RES_F_VC; |
| } |
| for (ns = 0; ns < statp->_u._ext.nscount; ns++) { |
| if (statp->_u._ext.nssocks[ns] != -1) { |
| (void) close(statp->_u._ext.nssocks[ns]); |
| statp->_u._ext.nssocks[ns] = -1; |
| } |
| } |
| } |
| |
| void res_ndestroy(res_state statp) { |
| res_nclose(statp); |
| if (statp->_u._ext.ext != NULL) free(statp->_u._ext.ext); |
| statp->options &= ~RES_INIT; |
| statp->_u._ext.ext = NULL; |
| } |
| |
| void res_setservers(res_state statp, const sockaddr_union* set, int cnt) { |
| int i, nserv; |
| size_t size; |
| |
| /* close open servers */ |
| res_nclose(statp); |
| |
| /* cause rtt times to be forgotten */ |
| statp->_u._ext.nscount = 0; |
| |
| nserv = 0; |
| for (i = 0; i < cnt && nserv < MAXNS; i++) { |
| switch (set->sin.sin_family) { |
| case AF_INET: |
| size = sizeof(set->sin); |
| if (statp->_u._ext.ext) |
| memcpy(&statp->_u._ext.ext->nsaddrs[nserv], &set->sin, size); |
| if (size <= sizeof(statp->nsaddr_list[nserv])) |
| memcpy(&statp->nsaddr_list[nserv], &set->sin, size); |
| else |
| statp->nsaddr_list[nserv].sin_family = 0; |
| nserv++; |
| break; |
| |
| #ifdef HAS_INET6_STRUCTS |
| case AF_INET6: |
| size = sizeof(set->sin6); |
| if (statp->_u._ext.ext) |
| memcpy(&statp->_u._ext.ext->nsaddrs[nserv], &set->sin6, size); |
| if (size <= sizeof(statp->nsaddr_list[nserv])) |
| memcpy(&statp->nsaddr_list[nserv], &set->sin6, size); |
| else |
| statp->nsaddr_list[nserv].sin_family = 0; |
| nserv++; |
| break; |
| #endif |
| |
| default: |
| break; |
| } |
| set++; |
| } |
| statp->nscount = nserv; |
| } |
| |
| int res_getservers(res_state statp, sockaddr_union* set, int cnt) { |
| int i; |
| size_t size; |
| uint16_t family; |
| |
| for (i = 0; i < statp->nscount && i < cnt; i++) { |
| if (statp->_u._ext.ext) |
| family = statp->_u._ext.ext->nsaddrs[i].sin.sin_family; |
| else |
| family = statp->nsaddr_list[i].sin_family; |
| |
| switch (family) { |
| case AF_INET: |
| size = sizeof(set->sin); |
| if (statp->_u._ext.ext) |
| memcpy(&set->sin, &statp->_u._ext.ext->nsaddrs[i], size); |
| else |
| memcpy(&set->sin, &statp->nsaddr_list[i], size); |
| break; |
| |
| #ifdef HAS_INET6_STRUCTS |
| case AF_INET6: |
| size = sizeof(set->sin6); |
| if (statp->_u._ext.ext) |
| memcpy(&set->sin6, &statp->_u._ext.ext->nsaddrs[i], size); |
| else |
| memcpy(&set->sin6, &statp->nsaddr_list[i], size); |
| break; |
| #endif |
| |
| default: |
| set->sin.sin_family = 0; |
| break; |
| } |
| set++; |
| } |
| return (statp->nscount); |
| } |
| |
| void res_setnetcontext(res_state statp, const struct android_net_context* netcontext) { |
| if (statp != NULL) { |
| statp->netid = netcontext->dns_netid; |
| statp->_mark = netcontext->dns_mark; |
| if (netcontext->flags & NET_CONTEXT_FLAG_USE_EDNS) { |
| statp->options |= RES_USE_EDNS0 | RES_USE_DNSSEC; |
| } |
| if (netcontext->flags & NET_CONTEXT_FLAG_USE_LOCAL_NAMESERVERS) { |
| statp->use_local_nameserver = true; |
| } |
| } |
| } |
