+/* Copyright (c) 2014, Ralf Jung <post@ralfj.de>
+ * 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 <iostream>
+#include <fstream>
+#include <sys/wait.h>
+
+#include <boost/regex.hpp>
#include <boost/property_tree/ptree.hpp>
#include <boost/property_tree/ini_parser.hpp>
+#include <boost/iostreams/device/file_descriptor.hpp>
+#include <boost/iostreams/stream.hpp>
-#include <sys/stat.h>
+using namespace boost;
+typedef property_tree::ptree::path_type path;
-int main(int argc, const char **argv)
+static void write(int fd, const char *str)
{
- if (argc < 2) {
- std::cerr << "Usage: " << argv[0] << " <configuration file>" << std::endl;
- return 1;
+ 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);
}
- const char *filename = argv[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_password("[a-zA-Z0-9.:;,_-]+");
+ static const regex regex_domain("[a-zA-Z0-9.]+");
+
- struct stat file_stat;
- int ret = lstat(filename, &file_stat);
- if (ret != 0) {
- std::cerr << "Unable to stat " << filename << "." << std::endl;
+ if (argc != 4) {
+ std::cerr << "Usage: " << argv[0] << " <domain> <password> <IP address>" << std::endl;
return 1;
}
- /* Check if the file is suited */
- if (!S_ISREG(file_stat.st_mode)) {
- std::cerr << filename << " is not a file." << std::endl;
- return 1;
+
+ /* Obtain input */
+ std::string domain = argv[1];
+ std::string password = argv[2];
+ std::string ip = argv[3];
+
+ /* Validate input */
+ if (!regex_match(ip, regex_ip)) {
+ std::cerr << "Invalid IP address " << ip << "." << std::endl;
+ exit(1);
}
- if (file_stat.st_uid != geteuid()) {
- std::cerr << filename << " must be owned by user executing " << argv[0] << "." << std::endl;
- return 1;
+ if (!regex_match(domain, regex_domain)) {
+ std::cerr << "Invalid domain " << domain << "." << std::endl;
+ exit(1);
}
- if (file_stat.st_mode & (S_IWGRP | S_IWOTH)) { /* can be written by group/others */
- std::cerr << filename << " must not be writeable by group or others." << std::endl;
- return 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 nsupdate = config.get<std::string>("nsupdate");
+ unsigned server_port = config.get<unsigned>("port", 53);
+
+ /* Given the domain, check whether the password matches */
+ optional<std::string> correct_password = config.get_optional<std::string>(path(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 */
+ 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);
}
- std::cout << "Hi world!" << std::endl;
return 0;
}
projects / dyn-nsupdate.git / blobdiff