From ce9aa4807ccecac078b0fb35c1dec2ae5f3618bd Mon Sep 17 00:00:00 2001 From: Brad House Date: Mon, 29 Apr 2024 13:17:47 -0400 Subject: [PATCH] Apple: reimplement DNS configuration reading (#750) The DNS configuration for apple is stored in the system configuration database. Apple does provide an emulated `/etc/resolv.conf` on MacOS (but not iOS), it cannot, however, represent the entirety of the DNS configuration. Alternatively, libresolv could be used to also retrieve some system configuration, but it too is not capable of retrieving the entirety of the DNS configuration. Attempts to use the preferred public API of `SCDynamicStoreCreate()` and friends yielded incomplete DNS information. Instead, that leaves some apple "internal" symbols from `configd` that we need to access in order to get the entire configuration. We can see that we're not the only ones to do this as Google Chrome also does: https://chromium.googlesource.com/chromium/src/+/HEAD/net/dns/dns_config_watcher_mac.cc These internal functions are what what`libresolv` and `scutil` use to retrieve the dns configuration. Since these symbols are not publicly available, we will dynamically load the symbols from `libSystem` and import the `dnsinfo.h` private header extracted from: https://opensource.apple.com/source/configd/configd-1109.140.1/dnsinfo/dnsinfo.h Fix By: Brad House (@bradh352) --- .github/workflows/codespell.yml | 2 +- .reuse/dep5 | 6 +- CMakeLists.txt | 2 +- LICENSES/APSL-2.0.txt | 102 +++++++++ configure.ac | 9 - src/lib/Makefile.inc | 1 + src/lib/ares_private.h | 21 +- src/lib/ares_sysconfig.c | 2 + src/lib/ares_sysconfig_files.c | 7 +- src/lib/ares_sysconfig_mac.c | 319 +++++++++++++++++++++++++++++ src/lib/ares_update_servers.c | 15 +- src/lib/thirdparty/apple/README.md | 4 + src/lib/thirdparty/apple/dnsinfo.h | 128 ++++++++++++ 13 files changed, 592 insertions(+), 26 deletions(-) create mode 100644 LICENSES/APSL-2.0.txt create mode 100644 src/lib/ares_sysconfig_mac.c create mode 100644 src/lib/thirdparty/apple/README.md create mode 100644 src/lib/thirdparty/apple/dnsinfo.h diff --git a/.github/workflows/codespell.yml b/.github/workflows/codespell.yml index 13eb5356..e22e21a2 100644 --- a/.github/workflows/codespell.yml +++ b/.github/workflows/codespell.yml @@ -30,4 +30,4 @@ jobs: sudo apt-get install codespell - name: spellcheck - run: codespell -I .github/scripts/codespell-ignore.txt include src + run: codespell -I .github/scripts/codespell-ignore.txt --skip="src/lib/thirdparty" include src diff --git a/.reuse/dep5 b/.reuse/dep5 index b4951d10..689c48b6 100644 --- a/.reuse/dep5 +++ b/.reuse/dep5 @@ -9,7 +9,7 @@ Copyright: The c-ares project and its contributors. License: MIT # Docs -Files: AUTHORS CHANGES CHANGES.0 CONTRIBUTING.md GIT-INFO NEWS README.cares README.md README.msvc RELEASE-NOTES RELEASE-PROCEDURE.md SECURITY.md TODO INSTALL.md test/README.md test/gmock-1.11.0/README.md +Files: AUTHORS CHANGES CHANGES.0 CONTRIBUTING.md GIT-INFO NEWS README.cares README.md README.msvc RELEASE-NOTES RELEASE-PROCEDURE.md SECURITY.md TODO INSTALL.md test/README.md test/gmock-1.11.0/README.md src/lib/thirdparty/apple/README.md Copyright: The c-ares project and its contributors. License: MIT @@ -30,3 +30,7 @@ License: FSFAP Files: m4/ax_code_coverage.m4 m4/pkg.m4 Copyright: see file License: LGPL-2.1-or-later + +Files: src/lib/thirdparty/apple/dnsinfo.h +Copyright: see file +License: APSL-2.0 diff --git a/CMakeLists.txt b/CMakeLists.txt index 164a6d49..4f7fd0f6 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -172,7 +172,7 @@ return 0; MACOS_V1012) ENDIF () -IF ((IOS OR APPLE OR ZOS) AND HAVE_LIBRESOLV) +IF (ZOS AND HAVE_LIBRESOLV) SET (CARES_USE_LIBRESOLV 1) ENDIF() diff --git a/LICENSES/APSL-2.0.txt b/LICENSES/APSL-2.0.txt new file mode 100644 index 00000000..2d2d2cf9 --- /dev/null +++ b/LICENSES/APSL-2.0.txt @@ -0,0 +1,102 @@ +APPLE PUBLIC SOURCE LICENSE +Version 2.0 - August 6, 2003 + +Please read this License carefully before downloading this software. By downloading or using this software, you are agreeing to be bound by the terms of this License. If you do not or cannot agree to the terms of this License, please do not download or use the software. + +Apple Note: In January 2007, Apple changed its corporate name from "Apple Computer, Inc." to "Apple Inc." This change has been reflected below and copyright years updated, but no other changes have been made to the APSL 2.0. + +1. General; Definitions. This License applies to any program or other work which Apple Inc. ("Apple") makes publicly available and which contains a notice placed by Apple identifying such program or work as "Original Code" and stating that it is subject to the terms of this Apple Public Source License version 2.0 ("License"). As used in this License: + + 1.1 "Applicable Patent Rights" mean: (a) in the case where Apple is the grantor of rights, (i) claims of patents that are now or hereafter acquired, owned by or assigned to Apple and (ii) that cover subject matter contained in the Original Code, but only to the extent necessary to use, reproduce and/or distribute the Original Code without infringement; and (b) in the case where You are the grantor of rights, (i) claims of patents that are now or hereafter acquired, owned by or assigned to You and (ii) that cover subject matter in Your Modifications, taken alone or in combination with Original Code. + + 1.2 "Contributor" means any person or entity that creates or contributes to the creation of Modifications. + + 1.3 "Covered Code" means the Original Code, Modifications, the combination of Original Code and any Modifications, and/or any respective portions thereof. + + 1.4 "Externally Deploy" means: (a) to sublicense, distribute or otherwise make Covered Code available, directly or indirectly, to anyone other than You; and/or (b) to use Covered Code, alone or as part of a Larger Work, in any way to provide a service, including but not limited to delivery of content, through electronic communication with a client other than You. + + 1.5 "Larger Work" means a work which combines Covered Code or portions thereof with code not governed by the terms of this License. + + 1.6 "Modifications" mean any addition to, deletion from, and/or change to, the substance and/or structure of the Original Code, any previous Modifications, the combination of Original Code and any previous Modifications, and/or any respective portions thereof. When code is released as a series of files, a Modification is: (a) any addition to or deletion from the contents of a file containing Covered Code; and/or (b) any new file or other representation of computer program statements that contains any part of Covered Code. + + 1.7 "Original Code" means (a) the Source Code of a program or other work as originally made available by Apple under this License, including the Source Code of any updates or upgrades to such programs or works made available by Apple under this License, and that has been expressly identified by Apple as such in the header file(s) of such work; and (b) the object code compiled from such Source Code and originally made available by Apple under this License + + 1.8 "Source Code" means the human readable form of a program or other work that is suitable for making modifications to it, including all modules it contains, plus any associated interface definition files, scripts used to control compilation and installation of an executable (object code). + + 1.9 "You" or "Your" means an individual or a legal entity exercising rights under this License. For legal entities, "You" or "Your" includes any entity which controls, is controlled by, or is under common control with, You, where "control" means (a) the power, direct or indirect, to cause the direction or management of such entity, whether by contract or otherwise, or (b) ownership of fifty percent (50%) or more of the outstanding shares or beneficial ownership of such entity. + +2. Permitted Uses; Conditions & Restrictions. Subject to the terms and conditions of this License, Apple hereby grants You, effective on the date You accept this License and download the Original Code, a world-wide, royalty-free, non-exclusive license, to the extent of Apple's Applicable Patent Rights and copyrights covering the Original Code, to do the following: + + 2.1 Unmodified Code. You may use, reproduce, display, perform, internally distribute within Your organization, and Externally Deploy verbatim, unmodified copies of the Original Code, for commercial or non-commercial purposes, provided that in each instance: + + (a) You must retain and reproduce in all copies of Original Code the copyright and other proprietary notices and disclaimers of Apple as they appear in the Original Code, and keep intact all notices in the Original Code that refer to this License; and + + (b) You must include a copy of this License with every copy of Source Code of Covered Code and documentation You distribute or Externally Deploy, and You may not offer or impose any terms on such Source Code that alter or restrict this License or the recipients' rights hereunder, except as permitted under Section 6. + + 2.2 Modified Code. You may modify Covered Code and use, reproduce, display, perform, internally distribute within Your organization, and Externally Deploy Your Modifications and Covered Code, for commercial or non-commercial purposes, provided that in each instance You also meet all of these conditions: + + (a) You must satisfy all the conditions of Section 2.1 with respect to the Source Code of the Covered Code; + + (b) You must duplicate, to the extent it does not already exist, the notice in Exhibit A in each file of the Source Code of all Your Modifications, and cause the modified files to carry prominent notices stating that You changed the files and the date of any change; and + + (c) If You Externally Deploy Your Modifications, You must make Source Code of all Your Externally Deployed Modifications either available to those to whom You have Externally Deployed Your Modifications, or publicly available. Source Code of Your Externally Deployed Modifications must be released under the terms set forth in this License, including the license grants set forth in Section 3 below, for as long as you Externally Deploy the Covered Code or twelve (12) months from the date of initial External Deployment, whichever is longer. You should preferably distribute the Source Code of Your Externally Deployed Modifications electronically (e.g. download from a web site). + + 2.3 Distribution of Executable Versions. In addition, if You Externally Deploy Covered Code (Original Code and/or Modifications) in object code, executable form only, You must include a prominent notice, in the code itself as well as in related documentation, stating that Source Code of the Covered Code is available under the terms of this License with information on how and where to obtain such Source Code. + + 2.4 Third Party Rights. You expressly acknowledge and agree that although Apple and each Contributor grants the licenses to their respective portions of the Covered Code set forth herein, no assurances are provided by Apple or any Contributor that the Covered Code does not infringe the patent or other intellectual property rights of any other entity. Apple and each Contributor disclaim any liability to You for claims brought by any other entity based on infringement of intellectual property rights or otherwise. As a condition to exercising the rights and licenses granted hereunder, You hereby assume sole responsibility to secure any other intellectual property rights needed, if any. For example, if a third party patent license is required to allow You to distribute the Covered Code, it is Your responsibility to acquire that license before distributing the Covered Code. + +3. Your Grants. In consideration of, and as a condition to, the licenses granted to You under this License, You hereby grant to any person or entity receiving or distributing Covered Code under this License a non-exclusive, royalty-free, perpetual, irrevocable license, under Your Applicable Patent Rights and other intellectual property rights (other than patent) owned or controlled by You, to use, reproduce, display, perform, modify, sublicense, distribute and Externally Deploy Your Modifications of the same scope and extent as Apple's licenses under Sections 2.1 and 2.2 above. + +4. Larger Works. You may create a Larger Work by combining Covered Code with other code not governed by the terms of this License and distribute the Larger Work as a single product. In each such instance, You must make sure the requirements of this License are fulfilled for the Covered Code or any portion thereof. + +5. Limitations on Patent License. Except as expressly stated in Section 2, no other patent rights, express or implied, are granted by Apple herein. Modifications and/or Larger Works may require additional patent licenses from Apple which Apple may grant in its sole discretion. + +6. Additional Terms. You may choose to offer, and to charge a fee for, warranty, support, indemnity or liability obligations and/or other rights consistent with the scope of the license granted herein ("Additional Terms") to one or more recipients of Covered Code. However, You may do so only on Your own behalf and as Your sole responsibility, and not on behalf of Apple or any Contributor. You must obtain the recipient's agreement that any such Additional Terms are offered by You alone, and You hereby agree to indemnify, defend and hold Apple and every Contributor harmless for any liability incurred by or claims asserted against Apple or such Contributor by reason of any such Additional Terms. + +7. Versions of the License. Apple may publish revised and/or new versions of this License from time to time. Each version will be given a distinguishing version number. Once Original Code has been published under a particular version of this License, You may continue to use it under the terms of that version. You may also choose to use such Original Code under the terms of any subsequent version of this License published by Apple. No one other than Apple has the right to modify the terms applicable to Covered Code created under this License. + +8. NO WARRANTY OR SUPPORT. The Covered Code may contain in whole or in part pre-release, untested, or not fully tested works. The Covered Code may contain errors that could cause failures or loss of data, and may be incomplete or contain inaccuracies. You expressly acknowledge and agree that use of the Covered Code, or any portion thereof, is at Your sole and entire risk. THE COVERED CODE IS PROVIDED "AS IS" AND WITHOUT WARRANTY, UPGRADES OR SUPPORT OF ANY KIND AND APPLE AND APPLE'S LICENSOR(S) (COLLECTIVELY REFERRED TO AS "APPLE" FOR THE PURPOSES OF SECTIONS 8 AND 9) AND ALL CONTRIBUTORS EXPRESSLY DISCLAIM ALL WARRANTIES AND/OR CONDITIONS, EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES AND/OR CONDITIONS OF MERCHANTABILITY, OF SATISFACTORY QUALITY, OF FITNESS FOR A PARTICULAR PURPOSE, OF ACCURACY, OF QUIET ENJOYMENT, AND NONINFRINGEMENT OF THIRD PARTY RIGHTS. APPLE AND EACH CONTRIBUTOR DOES NOT WARRANT AGAINST INTERFERENCE WITH YOUR ENJOYMENT OF THE COVERED CODE, THAT THE FUNCTIONS CONTAINED IN THE COVERED CODE WILL MEET YOUR REQUIREMENTS, THAT THE OPERATION OF THE COVERED CODE WILL BE UNINTERRUPTED OR ERROR-FREE, OR THAT DEFECTS IN THE COVERED CODE WILL BE CORRECTED. NO ORAL OR WRITTEN INFORMATION OR ADVICE GIVEN BY APPLE, AN APPLE AUTHORIZED REPRESENTATIVE OR ANY CONTRIBUTOR SHALL CREATE A WARRANTY. You acknowledge that the Covered Code is not intended for use in the operation of nuclear facilities, aircraft navigation, communication systems, or air traffic control machines in which case the failure of the Covered Code could lead to death, personal injury, or severe physical or environmental damage. + +9. LIMITATION OF LIABILITY. TO THE EXTENT NOT PROHIBITED BY LAW, IN NO EVENT SHALL APPLE OR ANY CONTRIBUTOR BE LIABLE FOR ANY INCIDENTAL, SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES ARISING OUT OF OR RELATING TO THIS LICENSE OR YOUR USE OR INABILITY TO USE THE COVERED CODE, OR ANY PORTION THEREOF, WHETHER UNDER A THEORY OF CONTRACT, WARRANTY, TORT (INCLUDING NEGLIGENCE), PRODUCTS LIABILITY OR OTHERWISE, EVEN IF APPLE OR SUCH CONTRIBUTOR HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES AND NOTWITHSTANDING THE FAILURE OF ESSENTIAL PURPOSE OF ANY REMEDY. SOME JURISDICTIONS DO NOT ALLOW THE LIMITATION OF LIABILITY OF INCIDENTAL OR CONSEQUENTIAL DAMAGES, SO THIS LIMITATION MAY NOT APPLY TO YOU. In no event shall Apple's total liability to You for all damages (other than as may be required by applicable law) under this License exceed the amount of fifty dollars ($50.00). + +10. Trademarks. This License does not grant any rights to use the trademarks or trade names "Apple", "Mac", "Mac OS", "QuickTime", "QuickTime Streaming Server" or any other trademarks, service marks, logos or trade names belonging to Apple (collectively "Apple Marks") or to any trademark, service mark, logo or trade name belonging to any Contributor. You agree not to use any Apple Marks in or as part of the name of products derived from the Original Code or to endorse or promote products derived from the Original Code other than as expressly permitted by and in strict compliance at all times with Apple's third party trademark usage guidelines which are posted at http://www.apple.com/legal/guidelinesfor3rdparties.html. + +11. Ownership. Subject to the licenses granted under this License, each Contributor retains all rights, title and interest in and to any Modifications made by such Contributor. Apple retains all rights, title and interest in and to the Original Code and any Modifications made by or on behalf of Apple ("Apple Modifications"), and such Apple Modifications will not be automatically subject to this License. Apple may, at its sole discretion, choose to license such Apple Modifications under this License, or on different terms from those contained in this License or may choose not to license them at all. + +12. Termination. + + 12.1 Termination. This License and the rights granted hereunder will terminate: + + (a) automatically without notice from Apple if You fail to comply with any term(s) of this License and fail to cure such breach within 30 days of becoming aware of such breach; + + (b) immediately in the event of the circumstances described in Section 13.5(b); or + + (c) automatically without notice from Apple if You, at any time during the term of this License, commence an action for patent infringement against Apple; provided that Apple did not first commence an action for patent infringement against You in that instance. + + 12.2 Effect of Termination. Upon termination, You agree to immediately stop any further use, reproduction, modification, sublicensing and distribution of the Covered Code. All sublicenses to the Covered Code which have been properly granted prior to termination shall survive any termination of this License. Provisions which, by their nature, should remain in effect beyond the termination of this License shall survive, including but not limited to Sections 3, 5, 8, 9, 10, 11, 12.2 and 13. No party will be liable to any other for compensation, indemnity or damages of any sort solely as a result of terminating this License in accordance with its terms, and termination of this License will be without prejudice to any other right or remedy of any party. + +13. Miscellaneous. + + 13.1 Government End Users. The Covered Code is a "commercial item" as defined in FAR 2.101. Government software and technical data rights in the Covered Code include only those rights customarily provided to the public as defined in this License. This customary commercial license in technical data and software is provided in accordance with FAR 12.211 (Technical Data) and 12.212 (Computer Software) and, for Department of Defense purchases, DFAR 252.227-7015 (Technical Data -- Commercial Items) and 227.7202-3 (Rights in Commercial Computer Software or Computer Software Documentation). Accordingly, all U.S. Government End Users acquire Covered Code with only those rights set forth herein. + + 13.2 Relationship of Parties. This License will not be construed as creating an agency, partnership, joint venture or any other form of legal association between or among You, Apple or any Contributor, and You will not represent to the contrary, whether expressly, by implication, appearance or otherwise. + + 13.3 Independent Development. Nothing in this License will impair Apple's right to acquire, license, develop, have others develop for it, market and/or distribute technology or products that perform the same or similar functions as, or otherwise compete with, Modifications, Larger Works, technology or products that You may develop, produce, market or distribute. + + 13.4 Waiver; Construction. Failure by Apple or any Contributor to enforce any provision of this License will not be deemed a waiver of future enforcement of that or any other provision. Any law or regulation which provides that the language of a contract shall be construed against the drafter will not apply to this License. + + 13.5 Severability. (a) If for any reason a court of competent jurisdiction finds any provision of this License, or portion thereof, to be unenforceable, that provision of the License will be enforced to the maximum extent permissible so as to effect the economic benefits and intent of the parties, and the remainder of this License will continue in full force and effect. (b) Notwithstanding the foregoing, if applicable law prohibits or restricts You from fully and/or specifically complying with Sections 2 and/or 3 or prevents the enforceability of either of those Sections, this License will immediately terminate and You must immediately discontinue any use of the Covered Code and destroy all copies of it that are in your possession or control. + + 13.6 Dispute Resolution. Any litigation or other dispute resolution between You and Apple relating to this License shall take place in the Northern District of California, and You and Apple hereby consent to the personal jurisdiction of, and venue in, the state and federal courts within that District with respect to this License. The application of the United Nations Convention on Contracts for the International Sale of Goods is expressly excluded. + + 13.7 Entire Agreement; Governing Law. This License constitutes the entire agreement between the parties with respect to the subject matter hereof. This License shall be governed by the laws of the United States and the State of California, except that body of California law concerning conflicts of law. + + Where You are located in the province of Quebec, Canada, the following clause applies: The parties hereby confirm that they have requested that this License and all related documents be drafted in English. Les parties ont exigé que le présent contrat et tous les documents connexes soient rédigés en anglais. + +EXHIBIT A. + +"Portions Copyright (c) 1999-2007 Apple Inc. All Rights Reserved. + +This file contains Original Code and/or Modifications of Original Code as defined in and that are subject to the Apple Public Source License Version 2.0 (the 'License'). You may not use this file except in compliance with the License. Please obtain a copy of the License at http://www.opensource.apple.com/apsl/ and read it before using this file. + +The Original Code and all software distributed under the License are distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. Please see the License for the specific language governing rights and limitations under the License." diff --git a/configure.ac b/configure.ac index 4d263a7f..cf622310 100644 --- a/configure.ac +++ b/configure.ac @@ -334,15 +334,6 @@ case $host_os in esac AC_MSG_RESULT($need_xnet) -dnl resolv lib for Apple (MacOS and iOS) -AS_IF([test "x$host_vendor" = "xapple"], [ - AC_SEARCH_LIBS([res_servicename], [resolv], [ - AC_DEFINE([CARES_USE_LIBRESOLV], [1], [Use resolver library to configure cares]) - ], [ - AC_MSG_ERROR([Unable to find libresolv which is required for iPhone targets]) - ]) -]) - dnl resolv lib for z/OS AS_IF([test "x$host_vendor" = "xibm" -a "x$host_os" = "xopenedition" ], [ AC_SEARCH_LIBS([res_init], [resolv], [ diff --git a/src/lib/Makefile.inc b/src/lib/Makefile.inc index 38f7a115..ceec3062 100644 --- a/src/lib/Makefile.inc +++ b/src/lib/Makefile.inc @@ -75,6 +75,7 @@ CSOURCES = ares__addrinfo2hostent.c \ ares_strsplit.c \ ares_sysconfig.c \ ares_sysconfig_files.c \ + ares_sysconfig_mac.c \ ares_timeout.c \ ares_update_servers.c \ ares_version.c \ diff --git a/src/lib/ares_private.h b/src/lib/ares_private.h index 89c5493f..47a70124 100644 --- a/src/lib/ares_private.h +++ b/src/lib/ares_private.h @@ -331,12 +331,12 @@ struct ares_channeldata { * The retry delay is the minimum time in milliseconds to wait between doing * such retries (applied per-server). */ - unsigned short server_retry_chance; - size_t server_retry_delay; + unsigned short server_retry_chance; + size_t server_retry_delay; /* Callback triggered when a server has a successful or failed response */ - ares_server_state_callback server_state_cb; - void *server_state_cb_data; + ares_server_state_callback server_state_cb; + void *server_state_cb_data; }; /* Does the domain end in ".onion" or ".onion."? Case-insensitive. */ @@ -430,10 +430,17 @@ typedef struct { ares_bool_t usevc; } ares_sysconfig_t; +ares_status_t ares__sysconfig_set_options(ares_sysconfig_t *sysconfig, + const char *str); + ares_status_t ares__init_by_environment(ares_sysconfig_t *sysconfig); ares_status_t ares__init_sysconfig_files(const ares_channel_t *channel, ares_sysconfig_t *sysconfig); +#ifdef __APPLE__ +ares_status_t ares__init_sysconfig_macos(ares_sysconfig_t *sysconfig); +#endif + ares_status_t ares__parse_sortlist(struct apattern **sortlist, size_t *nsort, const char *str); @@ -604,9 +611,9 @@ void ares_queue_notify_empty(ares_channel_t *channel); } \ } while (0) -#define ARES_CONFIG_CHECK(x) \ - (x && x->lookups && ares__slist_len(x->servers) > 0 && \ - x->timeout > 0 && x->tries > 0) +#define ARES_CONFIG_CHECK(x) \ + (x && x->lookups && ares__slist_len(x->servers) > 0 && x->timeout > 0 && \ + x->tries > 0) ares_bool_t ares__subnet_match(const struct ares_addr *addr, const struct ares_addr *subnet, diff --git a/src/lib/ares_sysconfig.c b/src/lib/ares_sysconfig.c index 9a2da416..e6a8a80e 100644 --- a/src/lib/ares_sysconfig.c +++ b/src/lib/ares_sysconfig.c @@ -1084,6 +1084,8 @@ ares_status_t ares__init_by_sysconfig(ares_channel_t *channel) status = ares__init_sysconfig_watt32(&sysconfig); #elif defined(ANDROID) || defined(__ANDROID__) status = ares__init_sysconfig_android(&sysconfig); +#elif defined(__APPLE__) + status = ares__init_sysconfig_macos(&sysconfig); #elif defined(CARES_USE_LIBRESOLV) status = ares__init_sysconfig_libresolv(&sysconfig); #else diff --git a/src/lib/ares_sysconfig_files.c b/src/lib/ares_sysconfig_files.c index 557888bc..5771a581 100644 --- a/src/lib/ares_sysconfig_files.c +++ b/src/lib/ares_sysconfig_files.c @@ -436,7 +436,8 @@ done: return status; } -static ares_status_t set_options(ares_sysconfig_t *sysconfig, const char *str) +ares_status_t ares__sysconfig_set_options(ares_sysconfig_t *sysconfig, + const char *str) { ares__buf_t *buf = NULL; ares__llist_t *options = NULL; @@ -494,7 +495,7 @@ ares_status_t ares__init_by_environment(ares_sysconfig_t *sysconfig) res_options = getenv("RES_OPTIONS"); if (res_options) { - status = set_options(sysconfig, res_options); + status = ares__sysconfig_set_options(sysconfig, res_options); if (status != ARES_SUCCESS) { return status; } @@ -617,7 +618,7 @@ static ares_status_t parse_resolvconf_line(ares_sysconfig_t *sysconfig, status = ARES_SUCCESS; } } else if (strcmp(option, "options") == 0) { - status = set_options(sysconfig, value); + status = ares__sysconfig_set_options(sysconfig, value); } return status; diff --git a/src/lib/ares_sysconfig_mac.c b/src/lib/ares_sysconfig_mac.c new file mode 100644 index 00000000..e7b3bf21 --- /dev/null +++ b/src/lib/ares_sysconfig_mac.c @@ -0,0 +1,319 @@ +/* MIT License + * + * Copyright (c) 2024 The c-ares project and its contributors + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice (including the next + * paragraph) shall be included in all copies or substantial portions of the + * Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + * + * SPDX-License-Identifier: MIT + */ + +#ifdef __APPLE__ + +/* The DNS configuration for apple is stored in the system configuration + * database. Apple does provide an emulated `/etc/resolv.conf` on MacOS (but + * not iOS), it cannot, however, represent the entirety of the DNS + * configuration. Alternatively, libresolv could be used to also retrieve some + * system configuration, but it too is not capable of retrieving the entirety + * of the DNS configuration. + * + * Attempts to use the preferred public API of `SCDynamicStoreCreate()` and + * friends yielded incomplete DNS information. Instead, that leaves some apple + * "internal" symbols from `configd` that we need to access in order to get the + * entire configuration. We can see that we're not the only ones to do this as + * Google Chrome also does: + * https://chromium.googlesource.com/chromium/src/+/HEAD/net/dns/dns_config_watcher_mac.cc + * These internal functions are what `libresolv` and `scutil` use to retrieve + * the dns configuration. Since these symbols are not publicly available, we + * will dynamically load the symbols from `libSystem` and import the `dnsinfo.h` + * private header extracted from: + * https://opensource.apple.com/source/configd/configd-1109.140.1/dnsinfo/dnsinfo.h + */ +# include "ares_setup.h" +# include +# include +# include +# include +# include +# include "thirdparty/apple/dnsinfo.h" +# include +# include "ares.h" +# include "ares_private.h" + +typedef struct { + void *handle; + const char *(*dns_configuration_notify_key)(void); + dns_config_t *(*dns_configuration_copy)(void); + void (*dns_configuration_free)(dns_config_t *config); +} dnsinfo_t; + +static void dnsinfo_destroy(dnsinfo_t *dnsinfo) +{ + if (dnsinfo == NULL) { + return; + } + + if (dnsinfo->handle) { + dlclose(dnsinfo->handle); + } + + ares_free(dnsinfo); +} + +static ares_status_t dnsinfo_init(dnsinfo_t **dnsinfo_out) +{ + dnsinfo_t *dnsinfo = NULL; + ares_status_t status = ARES_SUCCESS; + + if (dnsinfo_out == NULL) { + status = ARES_EFORMERR; + goto done; + } + + *dnsinfo_out = NULL; + + dnsinfo = ares_malloc_zero(sizeof(*dnsinfo)); + + if (dnsinfo == NULL) { + status = ARES_ENOMEM; + goto done; + } + + dnsinfo->handle = dlopen("/usr/lib/libSystem.dylib", RTLD_LAZY | RTLD_NOLOAD); + if (dnsinfo->handle == NULL) { + status = ARES_ESERVFAIL; + goto done; + } + + dnsinfo->dns_configuration_notify_key = + dlsym(dnsinfo->handle, "dns_configuration_notify_key"); + dnsinfo->dns_configuration_copy = + dlsym(dnsinfo->handle, "dns_configuration_copy"); + dnsinfo->dns_configuration_free = + dlsym(dnsinfo->handle, "dns_configuration_free"); + + if (dnsinfo->dns_configuration_notify_key == NULL || + dnsinfo->dns_configuration_copy == NULL || + dnsinfo->dns_configuration_free == NULL) { + status = ARES_ESERVFAIL; + goto done; + } + + +done: + if (status == ARES_SUCCESS) { + *dnsinfo_out = dnsinfo; + } else { + dnsinfo_destroy(dnsinfo); + } + + return status; +} + +static ares_bool_t search_is_duplicate(const ares_sysconfig_t *sysconfig, + const char *name) +{ + size_t i; + for (i = 0; i < sysconfig->ndomains; i++) { + if (strcasecmp(sysconfig->domains[i], name) == 0) { + return ARES_TRUE; + } + } + return ARES_FALSE; +} + +static ares_status_t read_resolver(const dns_resolver_t *resolver, + ares_sysconfig_t *sysconfig) +{ + int i; + unsigned short port = 0; + ares_status_t status = ARES_SUCCESS; + + /* XXX: resolver->domain is for domain-specific servers. When we implement + * this support, we'll want to use this. But for now, we're going to + * skip any servers which set this since we can't properly route. */ + if (resolver->domain != NULL) { + return ARES_SUCCESS; + } + + /* Check to see if DNS server should be used, base this on if the server is + * reachable or can be reachable automatically if we send traffic that + * direction. */ + if (!(resolver->reach_flags & + (kSCNetworkFlagsReachable | + kSCNetworkReachabilityFlagsConnectionOnTraffic))) { + return ARES_SUCCESS; + } + + /* NOTE: it doesn't look like resolver->flags is relevant */ + + /* If there's no nameservers, nothing to do */ + if (resolver->n_nameserver <= 0) { + return ARES_SUCCESS; + } + + /* Default port */ + port = resolver->port; + + /* Append search list */ + if (resolver->n_search > 0) { + char **new_domains = + ares_realloc_zero(sysconfig->domains, + sizeof(*sysconfig->domains) * sysconfig->ndomains, + sizeof(*sysconfig->domains) * + (sysconfig->ndomains + (size_t)resolver->n_search)); + if (new_domains == NULL) { + return ARES_ENOMEM; + } + sysconfig->domains = new_domains; + + for (i = 0; i < resolver->n_search; i++) { + /* Skip duplicates */ + if (search_is_duplicate(sysconfig, resolver->search[i])) { + continue; + } + sysconfig->domains[sysconfig->ndomains] = + ares_strdup(resolver->search[i]); + if (sysconfig->domains[sysconfig->ndomains] == NULL) { + return ARES_ENOMEM; + } + sysconfig->ndomains++; + } + } + + /* NOTE: we're going to skip importing the sort addresses for now. Its + * likely not used, its not obvious how to even configure such a thing. + */ +# if 0 + for (i=0; in_sortaddr; i++) { + char val[256]; + inet_ntop(AF_INET, &resolver->sortaddr[i]->address, val, sizeof(val)); + printf("\t\t%s/", val); + inet_ntop(AF_INET, &resolver->sortaddr[i]->mask, val, sizeof(val)); + printf("%s\n", val); + } +# endif + + if (resolver->options != NULL) { + status = ares__sysconfig_set_options(sysconfig, resolver->options); + if (status != ARES_SUCCESS) { + return status; + } + } + + /* NOTE: + * - resolver->timeout appears unused, always 0, so we ignore this + * - resolver->service_identifier doesn't appear relevant to us + * - resolver->cid also isn't relevant + * - resolver->if_index we don't need, if_name is used instead. + */ + + /* XXX: resolver->search_order appears like it might be relevant, we might + * need to sort the resulting list by this metric if we find in the future we + * need to. That said, due to the automatic re-sorting we do, I'm not sure it + * matters. Here's an article on this search order stuff: + * https://www.cnet.com/tech/computing/os-x-10-6-3-and-dns-server-priority-changes/ + */ + + for (i = 0; i < resolver->n_nameserver; i++) { + struct ares_addr addr; + unsigned short addrport; + + if (resolver->nameserver[i]->sa_family == AF_INET) { + struct sockaddr_in *addr_in = + (struct sockaddr_in *)(void *)resolver->nameserver[i]; + addr.family = AF_INET; + memcpy(&addr.addr.addr4, &(addr_in->sin_addr), sizeof(addr.addr.addr4)); + addrport = addr_in->sin_port; + } else if (resolver->nameserver[i]->sa_family == AF_INET6) { + struct sockaddr_in6 *addr_in6 = + (struct sockaddr_in6 *)(void *)resolver->nameserver[i]; + addr.family = AF_INET6; + memcpy(&addr.addr.addr6, &(addr_in6->sin6_addr), sizeof(addr.addr.addr6)); + addrport = addr_in6->sin6_port; + } else { + continue; + } + + if (addrport == 0) { + addrport = port; + } + status = ares__sconfig_append(&sysconfig->sconfig, &addr, addrport, + addrport, resolver->if_name); + if (status != ARES_SUCCESS) { + return status; + } + } + + return status; +} + +static ares_status_t read_resolvers(dns_resolver_t **resolvers, int nresolvers, + ares_sysconfig_t *sysconfig) +{ + ares_status_t status = ARES_SUCCESS; + int i; + + for (i = 0; status == ARES_SUCCESS && i < nresolvers; i++) { + status = read_resolver(resolvers[i], sysconfig); + } + + return status; +} + +ares_status_t ares__init_sysconfig_macos(ares_sysconfig_t *sysconfig) +{ + dnsinfo_t *dnsinfo = NULL; + dns_config_t *sc_dns = NULL; + ares_status_t status = ARES_SUCCESS; + + status = dnsinfo_init(&dnsinfo); + + if (status != ARES_SUCCESS) { + goto done; + } + + sc_dns = dnsinfo->dns_configuration_copy(); + if (sc_dns == NULL) { + status = ARES_ESERVFAIL; + goto done; + } + + /* There are `resolver`, `scoped_resolver`, and `service_specific_resolver` + * settings. The `scoped_resolver` settings appear to be already available via + * the `resolver` settings and likely are only relevant to link-local dns + * servers which we can already detect via the address itself, so we'll ignore + * the `scoped_resolver` section. It isn't clear what the + * `service_specific_resolver` is used for, I haven't personally seen it + * in use so we'll ignore this until at some point where we find we need it. + * Likely this wasn't available via `/etc/resolv.conf` nor `libresolv` anyhow + * so its not worse to prior configuration methods, worst case. */ + + status = read_resolvers(sc_dns->resolver, sc_dns->n_resolver, sysconfig); + +done: + if (dnsinfo) { + dnsinfo->dns_configuration_free(sc_dns); + dnsinfo_destroy(dnsinfo); + } + return status; +} + + +#endif diff --git a/src/lib/ares_update_servers.c b/src/lib/ares_update_servers.c index 36ebbaa9..1d279a3b 100644 --- a/src/lib/ares_update_servers.c +++ b/src/lib/ares_update_servers.c @@ -370,6 +370,7 @@ static ares_status_t ares__sconfig_linklocal(ares_sconfig_t *s, return ARES_SUCCESS; } + ares_status_t ares__sconfig_append(ares__llist_t **sconfig, const struct ares_addr *addr, unsigned short udp_port, @@ -405,10 +406,16 @@ ares_status_t ares__sconfig_append(ares__llist_t **sconfig, s->udp_port = udp_port; s->tcp_port = tcp_port; - /* Handle link-local enumeration */ - if (ares_strlen(ll_iface) && ares__addr_is_linklocal(&s->addr)) { + /* Handle link-local enumeration. If an interface is specified on a + * non-link-local address, we'll simply end up ignoring that */ + if (ares__addr_is_linklocal(&s->addr)) { + if (ares_strlen(ll_iface) == 0) { + /* Silently ignore this entry, we require an interface */ + status = ARES_SUCCESS; + goto fail; + } status = ares__sconfig_linklocal(s, ll_iface); - /* Silently ignore this entry */ + /* Silently ignore this entry, we can't validate the interface */ if (status != ARES_SUCCESS) { status = ARES_SUCCESS; goto fail; @@ -713,7 +720,7 @@ ares_status_t ares__servers_update(ares_channel_t *channel, const ares_sconfig_t *sconfig = ares__llist_node_val(node); ares__slist_node_t *snode; - /* Don't add duplicate servers! */ + /* If a server has already appeared in the list of new servers, skip it. */ if (ares__server_isdup(channel, node)) { continue; } diff --git a/src/lib/thirdparty/apple/README.md b/src/lib/thirdparty/apple/README.md new file mode 100644 index 00000000..e0915f4a --- /dev/null +++ b/src/lib/thirdparty/apple/README.md @@ -0,0 +1,4 @@ +The `dnsinfo.h` header was extracted from Apple's OpenSource repository: +[https://opensource.apple.com/source/configd/configd-1109.140.1/dnsinfo/dnsinfo.h](https://opensource.apple.com/source/configd/configd-1109.140.1/dnsinfo/dnsinfo.h) + +This is needed to call into `dns_configuration_copy()` and `dns_configuration_free()`. diff --git a/src/lib/thirdparty/apple/dnsinfo.h b/src/lib/thirdparty/apple/dnsinfo.h new file mode 100644 index 00000000..d5a0e70e --- /dev/null +++ b/src/lib/thirdparty/apple/dnsinfo.h @@ -0,0 +1,128 @@ +/* + * Copyright (c) 2004-2006, 2008, 2009, 2011-2013, 2015-2018 Apple Inc. All rights reserved. + * + * @APPLE_LICENSE_HEADER_START@ + * + * This file contains Original Code and/or Modifications of Original Code + * as defined in and that are subject to the Apple Public Source License + * Version 2.0 (the 'License'). You may not use this file except in + * compliance with the License. Please obtain a copy of the License at + * http://www.opensource.apple.com/apsl/ and read it before using this + * file. + * + * The Original Code and all software distributed under the License are + * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER + * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, + * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. + * Please see the License for the specific language governing rights and + * limitations under the License. + * + * @APPLE_LICENSE_HEADER_END@ + */ + +#ifndef __DNSINFO_H__ +#define __DNSINFO_H__ + +/* + * These routines provide access to the systems DNS configuration + */ + +#include +#include +#include +#include +#include +#include + +#define DNSINFO_VERSION 20170629 + +#define DEFAULT_SEARCH_ORDER 200000 /* search order for the "default" resolver domain name */ + +#define DNS_PTR(type, name) \ + union { \ + type name; \ + uint64_t _ ## name ## _p; \ + } + +#define DNS_VAR(type, name) \ + type name + + +#pragma pack(4) +typedef struct { + struct in_addr address; + struct in_addr mask; +} dns_sortaddr_t; +#pragma pack() + + +#pragma pack(4) +typedef struct { + DNS_PTR(char *, domain); /* domain */ + DNS_VAR(int32_t, n_nameserver); /* # nameserver */ + DNS_PTR(struct sockaddr **, nameserver); + DNS_VAR(uint16_t, port); /* port (in host byte order) */ + DNS_VAR(int32_t, n_search); /* # search */ + DNS_PTR(char **, search); + DNS_VAR(int32_t, n_sortaddr); /* # sortaddr */ + DNS_PTR(dns_sortaddr_t **, sortaddr); + DNS_PTR(char *, options); /* options */ + DNS_VAR(uint32_t, timeout); /* timeout */ + DNS_VAR(uint32_t, search_order); /* search_order */ + DNS_VAR(uint32_t, if_index); + DNS_VAR(uint32_t, flags); + DNS_VAR(uint32_t, reach_flags); /* SCNetworkReachabilityFlags */ + DNS_VAR(uint32_t, service_identifier); + DNS_PTR(char *, cid); /* configuration identifer */ + DNS_PTR(char *, if_name); /* if_index interface name */ +} dns_resolver_t; +#pragma pack() + + +#define DNS_RESOLVER_FLAGS_REQUEST_A_RECORDS 0x0002 /* always requesting for A dns records in queries */ +#define DNS_RESOLVER_FLAGS_REQUEST_AAAA_RECORDS 0x0004 /* always requesting for AAAA dns records in queries */ + +#define DNS_RESOLVER_FLAGS_REQUEST_ALL_RECORDS \ + (DNS_RESOLVER_FLAGS_REQUEST_A_RECORDS | DNS_RESOLVER_FLAGS_REQUEST_AAAA_RECORDS) + +#define DNS_RESOLVER_FLAGS_SCOPED 0x1000 /* configuration is for scoped questions */ +#define DNS_RESOLVER_FLAGS_SERVICE_SPECIFIC 0x2000 /* configuration is service-specific */ +#define DNS_RESOLVER_FLAGS_SUPPLEMENTAL 0x4000 /* supplemental match configuration */ + + +#pragma pack(4) +typedef struct { + DNS_VAR(int32_t, n_resolver); /* resolver configurations */ + DNS_PTR(dns_resolver_t **, resolver); + DNS_VAR(int32_t, n_scoped_resolver); /* "scoped" resolver configurations */ + DNS_PTR(dns_resolver_t **, scoped_resolver); + DNS_VAR(uint64_t, generation); + DNS_VAR(int32_t, n_service_specific_resolver); + DNS_PTR(dns_resolver_t **, service_specific_resolver); + DNS_VAR(uint32_t, version); +} dns_config_t; +#pragma pack() + + +__BEGIN_DECLS + +/* + * DNS configuration access APIs + */ +const char * +dns_configuration_notify_key (void) API_AVAILABLE(macos(10.4), ios(2.0)); + +dns_config_t * +dns_configuration_copy (void) API_AVAILABLE(macos(10.4), ios(2.0)); + +void +dns_configuration_free (dns_config_t *config) API_AVAILABLE(macos(10.4), ios(2.0)); + +void +_dns_configuration_ack (dns_config_t *config, + const char *bundle_id) API_AVAILABLE(macos(10.8), ios(6.0)); + +__END_DECLS + +#endif /* __DNSINFO_H__ */