[PATCH] [WIP]tools: add devname2tmpfile

This tool reads modules.devname from the current kernel directory and writes the information
out in the tmpfiles format so that systemd-tmpfiles can use this to create the required device
nodes before systemd-udevd is started on boot.

This makes sure nothing but kmod reads the private files under
/usr/lib/modules/.

Cc: <[email protected]>
Cc: <[email protected]>
---
 Makefile.am             |   3 +-
 tools/devname2tmpfile.c | 126 ++++++++++++++++++++++++++++++++++++++++++++++++
 tools/kmod.c            |   1 +
 tools/kmod.h            |   1 +
 4 files changed, 130 insertions(+), 1 deletion(-)
 create mode 100644 tools/devname2tmpfile.c

diff --git a/Makefile.am b/Makefile.am
index 9feaf96..50cd380 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -109,7 +109,8 @@ noinst_SCRIPTS = tools/insmod tools/rmmod tools/lsmod \
 tools_kmod_SOURCES = tools/kmod.c tools/kmod.h tools/lsmod.c \
 		     tools/rmmod.c tools/insmod.c \
 		     tools/modinfo.c tools/modprobe.c \
-		     tools/depmod.c tools/log.h tools/log.c
+		     tools/depmod.c tools/log.h tools/log.c \
+		     tools/devname2tmpfile.c
 tools_kmod_LDADD = libkmod/libkmod-util.la \
 		   libkmod/libkmod.la
 
diff --git a/tools/devname2tmpfile.c b/tools/devname2tmpfile.c
new file mode 100644
index 0000000..05a2b4e
--- /dev/null
+++ b/tools/devname2tmpfile.c
@@ -0,0 +1,126 @@
+/*
+ * kmod-devname2tmpfile - write devnames of current kernel in tmpfiles.d format
+ *
+ * Copyright (C) 2004-2012 Kay Sievers <[email protected]>
+ * Copyright (C) 2011-2013  ProFUSION embedded systems
+ * Copyright (C) 2013 Tom Gundersen <[email protected]>
+ *
+ * This program 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 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <errno.h>
+#include <unistd.h>
+#include <string.h>
+#include <limits.h>
+#include <sys/utsname.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include "libkmod.h"
+
+#include "kmod.h"
+
+static int do_devname2tmpfile(int argc, char *argv[])
+{
+        struct kmod_ctx *ctx;
+        struct utsname kernel;
+        const char *null_config = NULL;
+        char modules[PATH_MAX];
+        char buf[4096];
+        FILE *f, *out;
+
+	if (argc != 1) {
+		fprintf(stderr, "Usage: %s\n", argv[0]);
+		return EXIT_FAILURE;
+	}
+
+	ctx = kmod_new(NULL, &null_config);
+	if (ctx == NULL) {
+		fputs("Error: kmod_new() failed!\n", stderr);
+		return EXIT_FAILURE;
+	}
+
+        if (uname(&kernel) < 0) {
+                fputs("Error: uname failed!\n", stderr);
+                return EXIT_FAILURE;
+        }
+        snprintf(modules, sizeof(modules), "/lib/modules/%s/modules.devname", kernel.release);
+        f = fopen(modules, "re");
+        if (f == NULL) {
+		fprintf(stderr, "Error: could not open %s/modules.devname!\n", kernel.release);
+                return EXIT_FAILURE;
+        }
+
+        if (mkdir("/run/tmpfiles.d/", 755) != 0 && errno != EEXIST) {
+		fputs("Error: /run/tmpfiles.d does not exist and could not be created!\n", stderr);
+                return EXIT_FAILURE;
+        }
+
+        out = fopen("/run/tmpfiles.d/kmod.conf", "we");
+        if (out == NULL) {
+		fputs("Error: could not create /run/tmpfiles.d/kmod.conf!\n", stderr);
+                return EXIT_FAILURE;
+        }
+
+        while (fgets(buf, sizeof(buf), f) != NULL) {
+                char *s;
+                const char *modname;
+                const char *devname;
+                const char *devno;
+                int maj, min;
+                char type;
+
+                if (buf[0] == '#')
+                        continue;
+
+                modname = buf;
+                s = strchr(modname, ' ');
+                if (s == NULL)
+                        continue;
+                s[0] = '\0';
+
+                devname = &s[1];
+                s = strchr(devname, ' ');
+                if (s == NULL)
+                        continue;
+                s[0] = '\0';
+
+                devno = &s[1];
+                s = strchr(devno, ' ');
+                if (s == NULL)
+                        s = strchr(devno, '\n');
+                if (s != NULL)
+                        s[0] = '\0';
+                if (sscanf(devno, "%c%u:%u", &type, &maj, &min) != 3)
+                        continue;
+
+                if (type != 'c' && type != 'b')
+                    continue;
+
+                fprintf(out, "%c /dev/%s 0600 - - - %u:%u\n", type, devname, maj, min);
+        }
+
+        fclose(f);
+	kmod_unref(ctx);
+
+        return EXIT_SUCCESS;
+}
+
+const struct kmod_cmd kmod_cmd_devname2tmpfile = {
+	.name = "devname2tmpfile",
+	.cmd = do_devname2tmpfile,
+	.help = "write devnames of current kernel in tmpfiles.d format",
+};
diff --git a/tools/kmod.c b/tools/kmod.c
index ebb8875..ff6518c 100644
--- a/tools/kmod.c
+++ b/tools/kmod.c
@@ -37,6 +37,7 @@ static const struct kmod_cmd kmod_cmd_help;
 static const struct kmod_cmd *kmod_cmds[] = {
 	&kmod_cmd_help,
 	&kmod_cmd_list,
+	&kmod_cmd_devname2tmpfile,
 };
 
 static const struct kmod_cmd *kmod_compat_cmds[] = {
diff --git a/tools/kmod.h b/tools/kmod.h
index 80fa4c2..6410ed5 100644
--- a/tools/kmod.h
+++ b/tools/kmod.h
@@ -35,5 +35,6 @@ extern const struct kmod_cmd kmod_cmd_compat_modprobe;
 extern const struct kmod_cmd kmod_cmd_compat_depmod;
 
 extern const struct kmod_cmd kmod_cmd_list;
+extern const struct kmod_cmd kmod_cmd_devname2tmpfile;
 
 #include "log.h"
-- 
1.8.2.1