X-Git-Url: https://git.ralfj.de/dyn-nsupdate.git/blobdiff_plain/7d0063d7a7006bfb7b8a3051f42285f894183d1c..fd7ec51f7295b7364355287ad3593e35986ab7c9:/dyn-nsupdate.cpp diff --git a/dyn-nsupdate.cpp b/dyn-nsupdate.cpp index cdd1dc4..f2243bd 100644 --- a/dyn-nsupdate.cpp +++ b/dyn-nsupdate.cpp @@ -1,56 +1,150 @@ +/* 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 using namespace boost; +typedef property_tree::ptree::path_type path; + +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) { static const regex regex_ip("\\d{1,3}.\\d{1,3}.\\d{1,3}.\\d{1,3}"); - static const regex regex_user("[a-zA-Z]+"); + static const regex regex_password("[a-zA-Z0-9.:;,_-]+"); + static const regex regex_domain("[a-zA-Z0-9.]+"); - if (argc != 5) { - std::cerr << "Usage: " << argv[0] << " " << std::endl; + if (argc != 4) { + std::cerr << "Usage: " << argv[0] << " " << std::endl; return 1; } - /* Obtain and validate inpit */ - std::string user = argv[1]; + /* Obtain input */ + std::string domain = argv[1]; std::string password = argv[2]; - std::string domain = argv[3]; - std::string ip = argv[4]; + std::string ip = argv[3]; + /* Validate input */ if (!regex_match(ip, regex_ip)) { std::cerr << "Invalid IP address " << ip << "." << std::endl; - return 1; + exit(1); } - if (!regex_match(user, regex_user)) { - std::cerr << "Invalid username " << user << "." << std::endl; - return 1; + if (!regex_match(domain, regex_domain)) { + std::cerr << "Invalid domain " << domain << "." << std::endl; + exit(1); + } + if (!regex_match(password, regex_password)) { + std::cerr << "Invalid password " << password << "." << std::endl; + exit(1); } /* read configuration */ property_tree::ptree config; property_tree::ini_parser::read_ini(CONFIG_FILE, config); - std::string keyfile = config.get("key"); + std::string nsupdate = config.get("nsupdate"); + unsigned server_port = config.get("port", 53); - /* Check username, password, domain */ - optional correct_password = config.get_optional(user+".password"); + /* Given the domain, check whether the password matches */ + optional correct_password = config.get_optional(path(domain+"/password", '/')); if (!correct_password || *correct_password != password) { - std::cerr << "Username or password incorrect." << std::endl; - return 1; + std::cerr << "Password incorrect." << std::endl; + exit(1); } - if (config.get(user+".domain") != domain) { - std::cerr << "Domain incorrect." << std::endl; - return 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); } - std::cout << "It's all right, using key " << keyfile << std::endl; + /* Send it the command */ + write(pipe_ends[1], "update delete "); + write(pipe_ends[1], domain.c_str()); + write(pipe_ends[1], ". A\n"); + write(pipe_ends[1], "update add "); + write(pipe_ends[1], domain.c_str()); + write(pipe_ends[1], ". 60 A "); + write(pipe_ends[1], ip.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); + } return 0; }