init commit

1 files changed, 202 insertions, 0 deletions

diff --git a/src/main.cpp b/src/main.cpp
new file mode 100644
index 0000000..724b479
--- /dev/null
+++ b/src/main.cpp
@@ -0,0 +1,202 @@
+// =====================================
+//   ERROR HANDING - FROM FCUTILS
+// =====================================
+
+#include <stdio.h>
+#include <stdarg.h>
+#include <errno.h>
+#include <string.h>
+#include <stdlib.h>
+
+#define FORMAT_MAX_SIZE 1024
+extern int errno;
+
+void format_with_errno(char * buf, size_t n, char const * format) {
+	char const * errstr = strerror(errno);
+	char fmt_err[256];
+
+	size_t i = 0,
+		   j = 0;
+	while(errstr[j] && i < sizeof(fmt_err) - 1) {
+		if((fmt_err[i++] = errstr[j++]) != '%')
+			continue;
+
+		if(i < sizeof(fmt_err) - 1) {
+			fmt_err[i++] = '%';
+		} else {
+			i--;
+		}
+	}
+
+	fmt_err[i] = '\0';
+
+	snprintf(buf, n, "%s: %s", format, fmt_err);
+}
+
+
+[[noreturn]] void die_errno(char const * format, ...) {
+	va_list vargs;
+	va_start (vargs, format);
+
+	char buf[FORMAT_MAX_SIZE];
+	format_with_errno(buf, sizeof(buf), format);
+	vfprintf(stderr, buf, vargs);
+	fprintf(stderr, "\n");
+	exit(1);
+
+	va_end(vargs);
+}
+
+[[noreturn]] void die(char const * format, ...) {
+	va_list vargs;
+	va_start (vargs, format);
+
+	vfprintf(stderr, format, vargs);
+	fprintf(stderr, "\n");
+
+	va_end(vargs);
+	exit(1);
+}
+
+void err(char const * format, ...) {
+	va_list vargs;
+	va_start (vargs, format);
+
+	vfprintf(stderr, format, vargs);
+	fprintf(stderr, "\n");
+
+	va_end(vargs);
+}
+
+// =============================================
+//   COMMAND LINE UTILITY
+// =============================================
+
+
+#include "wg2sd.hpp"
+
+#include <filesystem>
+#include <fstream>
+#include <iostream>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <grp.h>
+
+[[noreturn]] void die_usage(char const * prog) {
+	err("Usage: %s [ -o OUTPUT_PATH ] CONFIG_FILE", prog);
+	die("Use -h for help");
+}
+
+void print_help(char const * prog) {
+	err("Usage: %s [ -o OUTPUT_PATH ] CONFIG_FILE", prog);
+	err("Options:");
+	err("-o OUTPUT_PATH\tSet the output path (default is /etc/systemd/network)");
+	err("-h\t\tDisplay this help message");
+	exit(EXIT_SUCCESS);
+}
+
+using namespace wg2sd;
+
+void write_systemd_file(SystemdFilespec const & filespec, std::string output_path, bool secure) {
+	std::string full_path = output_path + "/" + filespec.name;
+	std::ofstream ofs;
+
+	if (secure) {
+		// Set permissions to 0640 before writing the file
+		umask(0027);
+
+		// Open the file
+		ofs.open(full_path, std::ios::out | std::ios::trunc);
+		if (!ofs.is_open()) {
+			die("Failed to open file %s for writing", full_path.c_str());
+		}
+
+		// Change ownership to root:systemd-network
+		struct group *grp;
+		grp = getgrnam("systemd-network");
+		if (grp == nullptr) {
+			die_errno("Failed to find the 'systemd-network' group");
+		}
+		if (chown(full_path.c_str(), 0, grp->gr_gid) != 0) {
+			die_errno("Failed to change ownership of file %s", full_path.c_str());
+		}
+
+		// Set permissions
+		if (chmod(full_path.c_str(), S_IRUSR | S_IWUSR | S_IRGRP) != 0) {
+			die_errno("Failed to set permissions for file %s", full_path.c_str());
+		}
+	} else {
+		ofs.open(full_path, std::ios::out | std::ios::trunc);
+		if (!ofs.is_open()) {
+			die_errno("Failed to open file %s for writing", full_path.c_str());
+		}
+	}
+
+	// Write the contents to the file
+	ofs << filespec.contents;
+
+	if (ofs.fail()) {
+		die("Failed to write to file %s", full_path.c_str());
+	}
+}
+
+int main(int argc, char ** argv) {
+	int opt;
+	std::filesystem::path output_path = "/etc/systemd/network";
+
+	while ((opt = getopt(argc, argv, "o:h")) != -1) {
+		switch (opt) {
+			case 'o':
+				output_path = optarg;
+				break;
+			case 'h':
+				print_help(argv[0]);
+				break;
+			default: /* '?' */
+				die_usage(argv[0]);
+		}
+	}
+
+	if (optind >= argc) {
+		die_usage(argv[0]);
+	}
+
+	std::filesystem::path config_path = argv[optind];
+	std::fstream cfg_stream { config_path };
+
+	if(!cfg_stream.is_open()) {
+		die("Failed to open config file %s", config_path.string().c_str());
+	}
+
+	std::string interface_name = interface_name_from_filename(config_path);
+
+	SystemdConfig cfg;
+
+	try {
+		cfg = wg2sd::wg2sd(interface_name, cfg_stream, output_path);
+	} catch(ConfigurationException const & cex) {
+
+		const ParsingException * pex = dynamic_cast<const ParsingException *>(&cex);
+		if(pex && pex->line_no().has_value()) {
+			die("parsing error (line %llu): %s", pex->line_no().value(), pex->what());
+		} else {
+			die("configuration error: %s", cex.what());
+		}
+
+	}
+
+	if(!std::filesystem::path(output_path).is_absolute()) {
+		output_path = std::filesystem::absolute(output_path);
+	}
+
+	write_systemd_file(cfg.netdev, output_path, false);
+	write_systemd_file(cfg.network, output_path, false);
+	write_systemd_file(cfg.private_keyfile, output_path, true);
+
+	for(SystemdFilespec const & spec : cfg.symmetric_keyfiles) {
+		write_systemd_file(spec, output_path, true);
+	}
+
+	return 0;
+}