mknod: New helper utility

2 files changed, 300 insertions, 0 deletions

diff --git a/helpers/local.mk b/helpers/local.mk
new file mode 100644
index 0000000..ce5ecc7
--- /dev/null
+++ b/helpers/local.mk
@@ -0,0 +1 @@
+mknod_SOURCES = %reldir%/mknod.c
diff --git a/helpers/mknod.c b/helpers/mknod.c
new file mode 100644
index 0000000..93ef974
--- /dev/null
+++ b/helpers/mknod.c
@@ -0,0 +1,299 @@
+/*
+ * Copyright (C) 2023  Patrick McDermott
+ *
+ * This file is part of opkg-opk.
+ *
+ * opkg-opk is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * opkg-opk is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with opkg-opk.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#ifdef ENABLE_NLS
+#include <locale.h>
+#include <libintl.h>
+#define _(msgid) gettext(msgid)
+#else
+#define _(msgid) (msgid)
+#endif
+
+#ifdef HAVE_GETOPT_LONG
+#include <getopt.h>
+#endif
+
+static const char *_OPTSTRING = "m:";
+#ifdef HAVE_GETOPT_LONG
+static const struct option _LONGOPTS[] = {
+	{
+		.name    = "mode",
+		.has_arg = 1,
+		.flag    = NULL,
+		.val     = 'm',
+	},
+};
+#endif
+
+static const unsigned int _TIMEOUT = 10U;
+
+int
+main(int argc, char *argv[])
+{
+	char          *program_name;
+	char          *work_area;
+	char         **exec_argv;
+	int            arg;
+	mode_t         mode;
+	int            opt;
+	char          *name;
+	char           type;
+	char          *end;
+	long int       major;
+	long int       minor;
+	char          *specials_file_name;
+	char          *specials_lock_name;
+	int            fd;
+	unsigned int   timeout;
+	int            specials_fd;
+	FILE          *specials_file;
+	struct stat    stat_buf;
+
+#ifdef ENABLE_NLS
+	bindtextdomain(GETTEXT_PACKAGE, LOCALEDIR);
+#ifdef HAVE_BIND_TEXTDOMAIN_CODESET
+	bind_textdomain_codeset(PACKAGE, "UTF-8");
+#endif
+	textdomain(PACKAGE);
+	setlocale(LC_ALL, "");
+#endif
+
+	program_name = argv[0];
+
+	work_area = getenv("OPK_WORK_AREA");
+	if (work_area == NULL || work_area[0] == '\0') {
+		fprintf(stderr, _("%s: OPK_WORK_AREA environment variable not "
+					"set\n"), program_name);
+		fprintf(stderr, _("%s: Possibly building package dependent on "
+					"opkg-opk with opkbuild too old to use "
+					"it\n"), program_name);
+		fprintf(stderr, _("%s: Executing system mknod instead\n"),
+			program_name);
+		exec_argv = calloc(argc + 1, sizeof(*exec_argv));
+		if (exec_argv == NULL) {
+			fprintf(stderr, _("%s: Failed to allocate memory\n"),
+					program_name);
+			return EXIT_FAILURE;
+		}
+		exec_argv[0] = malloc(strlen(MKNOD) + 1);
+		if (exec_argv[0] == NULL) {
+			fprintf(stderr, _("%s: Failed to allocate memory\n"),
+					program_name);
+			free(exec_argv);
+			return EXIT_FAILURE;
+		}
+		strcpy(exec_argv[0], MKNOD);
+		for (arg = 1; arg < argc; ++arg) {
+			exec_argv[arg] = argv[arg];
+		}
+		exec_argv[argc] = NULL;
+		execve(MKNOD, exec_argv, NULL);  /* Shouldn't return */
+		fprintf(stderr, _("%s: Failed to execute system mknod\n"),
+				program_name);
+		free(exec_argv[0]);
+		free(exec_argv);
+		return EXIT_FAILURE;
+	}
+
+	mode = 0;
+#ifdef HAVE_GETOPT_LONG
+	while ((opt = getopt_long(argc, argv, _OPTSTRING, _LONGOPTS, NULL))
+			!= -1) {
+#else
+	while ((opt = getopt(argc, argv, _OPTSTRING)) != -1) {
+#endif
+		switch(opt) {
+			case 'm':
+				/* TODO: Parse mode. */
+				break;
+			default:
+				fprintf(stderr, _("%s: Warning: Unknown option:"
+							" \"%c\"\n"),
+						program_name, optopt);
+				return EXIT_FAILURE;
+		}
+	}
+	argc -= optind;
+	argv += optind;
+
+	if (argc < 2) {
+		fprintf(stderr, _("%s: Wrong number of operands\n"),
+				program_name);
+		return EXIT_FAILURE;
+	}
+	name = argv[0];
+	switch (argv[1][0]) {
+		case 'c':
+		case 'u':
+			type = 'c';
+			break;
+		case 'b':
+			type = 'b';
+			break;
+		case 'p':
+			if (argc != 2) {
+				fprintf(stderr, _("%s: Wrong number of "
+							"operands\n"),
+						program_name);
+				return EXIT_FAILURE;
+			}
+			if (mkfifo(name, mode) != 0) {
+				fprintf(stderr, _("%s: Failed to create link "
+							"\"%s\"\n"),
+						program_name, name);
+				return EXIT_FAILURE;
+			}
+			return EXIT_SUCCESS;
+		default:
+			fprintf(stderr, _("%s: Invalid node type \"%c\"\n"),
+						program_name, argv[1][0]);
+			return EXIT_FAILURE;
+	}
+
+	if (argc != 4) {
+		fprintf(stderr, _("%s: Wrong number of operands\n"),
+				program_name);
+		return EXIT_FAILURE;
+	}
+	major = strtol(argv[2], &end, 10);
+	if (*end != '\0') {
+		fprintf(stderr, _("%s: Invalid number \"%s\"\n"),
+				program_name, argv[2]);
+		return EXIT_FAILURE;
+	}
+	minor = strtol(argv[3], &end, 10);
+	if (*end != '\0') {
+		fprintf(stderr, _("%s: Invalid number \"%s\"\n"),
+				program_name, argv[3]);
+		return EXIT_FAILURE;
+	}
+
+	specials_file_name = malloc(strlen(work_area) + strlen("/specials")
+			+ 1 /* "\0" */);
+	if (specials_file_name == NULL) {
+		fprintf(stderr, _("%s: Failed to allocate memory\n"),
+				program_name);
+		return EXIT_FAILURE;
+	}
+	specials_lock_name = malloc(strlen(work_area) + strlen("/specials~")
+			+ 1 /* "\0" */);
+	if (specials_lock_name == NULL) {
+		fprintf(stderr, _("%s: Failed to allocate memory\n"),
+				program_name);
+		free(specials_file_name);
+		return EXIT_FAILURE;
+	}
+	sprintf(specials_file_name, "%s/specials",  work_area);
+	sprintf(specials_lock_name, "%s/specials~", work_area);
+
+	/* Create the named node.  This should be done before appending to the
+	 * specials file, in case a file by the specified name already exists.
+	 */
+	fd = open(name, O_CREAT | O_EXCL, mode);
+	if (fd < 0 || close(fd) < 0) {
+		fprintf(stderr, _("%s: Failed to create node\n"), program_name);
+		free(specials_file_name);
+		free(specials_lock_name);
+		return EXIT_FAILURE;
+	}
+
+	/* Acquire lock ("specials~"). */
+	for (timeout = _TIMEOUT; timeout > 0; --timeout) {
+		specials_fd = open(specials_lock_name, O_CREAT | O_EXCL, 0644);
+		if (specials_fd >= 0) {
+			goto opened;
+		}
+	}
+	fprintf(stderr, _("%s: Failed to lock specials file\n"), program_name);
+	free(specials_file_name);
+	free(specials_lock_name);
+	unlink(name);
+	return EXIT_FAILURE;
+
+ opened:
+	specials_file = fdopen(specials_fd, "a");
+	if (specials_file == NULL) {
+		fprintf(stderr, _("%s: Failed to open specials file stream\n"),
+				program_name);
+		close(specials_fd);
+		free(specials_file_name);
+		free(specials_lock_name);
+		unlink(name);
+		return EXIT_FAILURE;
+	}
+
+	/* If "specials" doesn't exist, write header. */
+	if (stat(specials_file_name, &stat_buf) != 0) {
+		if (errno != ENOENT) {
+			fprintf(stderr, _("%s: Failed to stat specials file\n"),
+					program_name);
+			fclose(specials_file);
+			free(specials_file_name);
+			free(specials_lock_name);
+			unlink(name);
+			return EXIT_FAILURE;
+		}
+		if (fputs("version=1\n", specials_file) < 0 ||
+				fputs("type     major     minor  name\n",
+					specials_file) < 0) {
+			fprintf(stderr, _("%s: Failed to write specials file\n")
+					, program_name);
+			fclose(specials_file);
+			free(specials_file_name);
+			free(specials_lock_name);
+			unlink(name);
+			return EXIT_FAILURE;
+		}
+	}
+	if (fprintf(specials_file, "%c  %8ld  %8ld  %s\n", type, major, minor,
+				name) < 0) {
+		fprintf(stderr, _("%s: Failed to write specials file\n"),
+				program_name);
+		fclose(specials_file);
+		free(specials_file_name);
+		free(specials_lock_name);
+		unlink(name);
+		return EXIT_FAILURE;
+	}
+	fclose(specials_file);
+
+	if (rename(specials_lock_name, specials_file_name) != 0) {
+		fprintf(stderr, _("%s: Failed to move specials file\n"),
+				program_name);
+		free(specials_file_name);
+		free(specials_lock_name);
+		unlink(name);
+		return EXIT_FAILURE;
+	}
+
+	free(specials_file_name);
+	free(specials_lock_name);
+
+	return EXIT_SUCCESS;
+}