X-Git-Url: https://git.ralfj.de/dyn-nsupdate.git/blobdiff_plain/e743a95875c0c204473c3d078312b638e667a055..9600b17be11c899d4c5d0be19eb96b3d67f1da39:/dyn-nsupdate.cpp?ds=sidebyside diff --git a/dyn-nsupdate.cpp b/dyn-nsupdate.cpp deleted file mode 100644 index d133369..0000000 --- a/dyn-nsupdate.cpp +++ /dev/null @@ -1,194 +0,0 @@ -/* Copyright (c) 2014, Ralf Jung -* 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. -* -* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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. -* -* The views and conclusions contained in the software and documentation are those -* of the authors and should not be interpreted as representing official policies, -* either expressed or implied, of the FreeBSD Project. -*/ - -#include -#include -#include - -#include -#include -#include -#include -#include -#include - -namespace pt = boost::property_tree; -namespace po = boost::program_options; -using std::string; -using boost::regex; -using boost::optional; - -static void write(int fd, const char *str) -{ - size_t len = strlen(str); - ssize_t written = write(fd, str, len); - if (written < 0 || (size_t)written != len) { - std::cerr << "Error writing pipe." << std::endl; - exit(1); - } -} - -int main(int argc, const char ** argv) -{ - try { - static const regex regex_ipv4("\\d{1,3}(\\.\\d{1,3}){3}|"); - static const regex regex_ipv6("[a-fA-F0-9]{1,4}(:[a-fA-F0-9]{1,4}){7}|"); - static const regex regex_password("[a-zA-Z0-9.:;,_-]+"); - static const regex regex_domain("[a-zA-Z0-9.]+"); - - // Declare the supported options. - po::options_description desc("Allowed options"); - desc.add_options() - ("help", "produce help message") - ("domain", po::value()->required(), "the domain to update") - ("password", po::value()->required(), "the password for the domain") - ("ipv4", po::value(), "the new IPv4 address (empty to delete the A record)") - ("ipv6", po::value(), "the new IPv6 address (empty to delete the AAAA record)") - ; - - // parse arguments - po::variables_map vm; - po::store(po::parse_command_line(argc, argv, desc), vm); - po::notify(vm); - if (vm.count("help")) { - std::cout << "dyn-nsupdate -- a safe setuid wrapper for nsupdate" << std::endl << std::endl; - std::cout << desc << "\n"; - return 1; - } - string domain = vm["domain"].as(); - string password = vm["password"].as(); - bool haveIPv4 = vm.count("ipv4"); - string ipv4 = haveIPv4 ? vm["ipv4"].as() : ""; - bool haveIPv6 = vm.count("ipv6"); - string ipv6 = haveIPv6 ? vm["ipv6"].as() : ""; - - /* Validate input */ - if (!regex_match(ipv4, regex_ipv4)) { - throw std::runtime_error("Invalid IPv4 address" + ipv4); - } - if (!regex_match(ipv6, regex_ipv6)) { - throw std::runtime_error("Invalid IPv6 address: " + ipv6); - } - if (!regex_match(domain, regex_domain)) { - throw std::runtime_error("Invalid Domain: " + domain); - } - if (!regex_match(password, regex_password)) { - throw std::runtime_error("Invalid Password: " + password); - } - - /* read configuration */ - pt::ptree config; - pt::ini_parser::read_ini(CONFIG_FILE, config); - std::string nsupdate = config.get("nsupdate"); - unsigned server_port = config.get("port", 53); - - /* Given the domain, check whether the password matches */ - optional correct_password = config.get_optional(pt::ptree::path_type(domain+"/password", '/')); - if (!correct_password || *correct_password != password) { - std::cerr << "Password incorrect." << std::endl; - exit(1); - } - - /* preapre the pipe */ - int pipe_ends[2]; - if (pipe(pipe_ends) < 0) { - std::cerr << "Error opening pipe." << std::endl; - exit(1); - } - - /* Launch nsupdate */ - pid_t child_pid = fork(); - if (child_pid < 0) { - std::cerr << "Error while forking." << std::endl; - exit(1); - } - if (child_pid == 0) { - /* We're in the child */ - /* Close write end, use read end as stdin */ - close(pipe_ends[1]); - if (dup2(pipe_ends[0], fileno(stdin)) < 0) { - std::cerr << "There was an error redirecting stdin." << std::endl; - exit(1); - } - /* exec nsupdate */ - execl(nsupdate.c_str(), nsupdate.c_str(), "-p", std::to_string(server_port).c_str(), "-l", (char *)NULL); - /* There was an error */ - std::cerr << "There was an error executing nsupdate." << std::endl; - exit(1); - } - - /* Send it the command */ - if (haveIPv4) { - write(pipe_ends[1], "update delete "); - write(pipe_ends[1], domain.c_str()); - write(pipe_ends[1], ". A\n"); - - if (!ipv4.empty()) { - write(pipe_ends[1], "update add "); - write(pipe_ends[1], domain.c_str()); - write(pipe_ends[1], ". 60 A "); - write(pipe_ends[1], ipv4.c_str()); - write(pipe_ends[1], "\n"); - } - } - - if (haveIPv6) { - write(pipe_ends[1], "update delete "); - write(pipe_ends[1], domain.c_str()); - write(pipe_ends[1], ". AAAA\n"); - - if (!ipv6.empty()) { - write(pipe_ends[1], "update add "); - write(pipe_ends[1], domain.c_str()); - write(pipe_ends[1], ". 60 AAAA "); - write(pipe_ends[1], ipv6.c_str()); - write(pipe_ends[1], "\n"); - } - } - - write(pipe_ends[1], "send\n"); - - /* Close both ends */ - close(pipe_ends[0]); - close(pipe_ends[1]); - - /* Wait for child to be gone */ - int child_status; - waitpid(child_pid, &child_status, 0); - if (child_status != 0) { - std::cerr << "There was an error in the child." << std::endl; - exit(1); - } - } - catch(std::exception &e) { - std::cout << e.what() << "\n"; - return 1; - } - - return 0; -}