mkbootfs: Add support for a dev node list file
Let mkbootfs create a list of dev nodes and directories, based on a
file:
$ mkbootfs -n node_file initramfs/ > initramfs.cpio
This file is following the same format as the kernel usr/ cpio list:
$ cat node_file
# My device nodes
dir dev 0755 0 0
nod dev/null 0600 0 0 c 1 5
Bug: 254835242
Change-Id: Ieb75b1d1026a9426581b6f2b3aa692a05722ba0d
diff --git a/mkbootfs/mkbootfs.c b/mkbootfs/mkbootfs.c
index 1b96788..907cad3 100644
--- a/mkbootfs/mkbootfs.c
+++ b/mkbootfs/mkbootfs.c
@@ -1,4 +1,6 @@
+#include <error.h>
+#include <errno.h>
#include <getopt.h>
#include <stdio.h>
#include <stdlib.h>
@@ -14,6 +16,8 @@
#include <stdarg.h>
#include <fcntl.h>
+#include <linux/kdev_t.h>
+
#include <private/android_filesystem_config.h>
#include <private/fs_config.h>
@@ -335,21 +339,123 @@
fclose(f);
}
+static void devnodes_desc_error(const char* filename, unsigned long line_num,
+ const char* msg)
+{
+ error(EXIT_FAILURE, 0, "failed to read nodes desc file '%s' line %lu: %s",
+ filename, line_num, msg);
+}
+
+static int append_devnodes_desc_dir(char* path, char* args)
+{
+ struct stat s;
+
+ if (sscanf(args, "%o %d %d", &s.st_mode, &s.st_uid, &s.st_gid) != 3) return -1;
+
+ s.st_mode |= S_IFDIR;
+
+ _eject(&s, path, strlen(path), NULL, 0);
+
+ return 0;
+}
+
+static int append_devnodes_desc_nod(char* path, char* args)
+{
+ int minor, major;
+ struct stat s;
+ char dev;
+
+ if (sscanf(args, "%o %d %d %c %d %d", &s.st_mode, &s.st_uid, &s.st_gid,
+ &dev, &major, &minor) != 6) return -1;
+
+ s.st_rdev = MKDEV(major, minor);
+ switch (dev) {
+ case 'b':
+ s.st_mode |= S_IFBLK;
+ break;
+ case 'c':
+ s.st_mode |= S_IFCHR;
+ break;
+ default:
+ return -1;
+ }
+
+ _eject(&s, path, strlen(path), NULL, 0);
+
+ return 0;
+}
+
+static void append_devnodes_desc(const char* filename)
+{
+ FILE* f = fopen(filename, "re");
+ if (!f) error(EXIT_FAILURE, errno,
+ "failed to open nodes description file '%s'", filename);
+
+ char *line, *args, *type, *path;
+ unsigned long line_num = 0;
+ size_t allocated_len;
+
+ while (getline(&line, &allocated_len, f) != -1) {
+ char* type;
+
+ line_num++;
+
+ if (*line == '#') continue;
+
+ if (!(type = strtok(line, " \t"))) {
+ devnodes_desc_error(filename, line_num, "a type is missing");
+ }
+
+ if (*type == '\n') continue;
+
+ if (!(path = strtok(NULL, " \t"))) {
+ devnodes_desc_error(filename, line_num, "a path is missing");
+ }
+
+ if (!(args = strtok(NULL, "\n"))) {
+ devnodes_desc_error(filename, line_num, "args are missing");
+ }
+
+ if (!strcmp(type, "dir")) {
+ if (append_devnodes_desc_dir(path, args)) {
+ devnodes_desc_error(filename, line_num, "bad arguments for dir");
+ }
+ } else if (!strcmp(type, "nod")) {
+ if (append_devnodes_desc_nod(path, args)) {
+ devnodes_desc_error(filename, line_num, "bad arguments for nod");
+ }
+ } else {
+ devnodes_desc_error(filename, line_num, "type unknown");
+ }
+ }
+
+ free(line);
+ fclose(f);
+}
+
static const struct option long_options[] = {
{ "dirname", required_argument, NULL, 'd' },
{ "file", required_argument, NULL, 'f' },
{ "help", no_argument, NULL, 'h' },
+ { "nodes", required_argument, NULL, 'n' },
{ NULL, 0, NULL, 0 },
};
static void usage(void)
{
fprintf(stderr,
- "Usage: mkbootfs [-d DIR|-F FILE] DIR...\n"
+ "Usage: mkbootfs [-n FILE] [-d DIR|-F FILE] DIR...\n"
"\n"
"\t-d, --dirname=DIR: fs-config directory\n"
"\t-f, --file=FILE: Canned configuration file\n"
"\t-h, --help: Print this help\n"
+ "\t-n, --nodes=FILE: Dev nodes description file\n"
+ "\nDev nodes description:\n"
+ "\t[dir|nod] [perms] [uid] [gid] [c|b] [minor] [major]\n"
+ "\tExample:\n"
+ "\t\t# My device nodes\n"
+ "\t\tdir dev 0755 0 0\n"
+ "\t\tnod dev/null 0600 0 0 c 1 5\n"
);
}
@@ -357,7 +463,7 @@
{
int opt, unused;
- while ((opt = getopt_long(argc, argv, "hd:f:", long_options, &unused)) != -1) {
+ while ((opt = getopt_long(argc, argv, "hd:f:n:", long_options, &unused)) != -1) {
switch (opt) {
case 'd':
target_out_path = argv[optind - 1];
@@ -368,6 +474,9 @@
case 'h':
usage();
return 0;
+ case 'n':
+ append_devnodes_desc(argv[optind - 1]);
+ break;
default:
usage();
die("Unknown option %s", argv[optind - 1]);