From 979038ba0da3ff61ddb61a809795189d3c25f71a Mon Sep 17 00:00:00 2001

From: Harald Hoyer <harald@redhat.com>

Date: Fri, 24 Jan 2014 15:27:51 +0100

Subject: [PATCH] add skipcpio utility

skipcpio skips a cpio archive at the beginning of a file.

It is used for skipping an early cpio archive for lsinitrd.

---

 Makefile            |  13 +++++-

 skipcpio/skipcpio.c | 123 ++++++++++++++++++++++++++++++++++++++++++++++++++++

 2 files changed, 135 insertions(+), 1 deletion(-)

 create mode 100644 skipcpio/skipcpio.c

diff --git a/Makefile b/Makefile

index e7da948..5441d8f 100644

--- a/Makefile

+++ b/Makefile

@@ -40,7 +40,7 @@ manpages = $(man1pages) $(man5pages) $(man7pages) $(man8pages)

 .PHONY: install clean archive rpm testimage test all check AUTHORS doc dracut-version.sh

-all: dracut-version.sh dracut-install

+all: dracut-version.sh dracut-install skipcpio/skipcpio

 DRACUT_INSTALL_OBJECTS = \

         install/dracut-install.o \

@@ -61,8 +61,15 @@ install/dracut-install: $(DRACUT_INSTALL_OBJECTS)

 dracut-install: install/dracut-install

 	ln -fs $< $@

+SKIPCPIO_OBJECTS= \

+	skipcpio/skipcpio.o

+

+skipcpio/skipcpio.o: skipcpio/skipcpio.c

+skipcpio/skipcpio: skipcpio/skipcpio.o

+

 indent:

 	indent -i8 -nut -br -linux -l120 install/dracut-install.c

+	indent -i8 -nut -br -linux -l120 skipcpio/skipcpio.c

 doc: $(manpages) dracut.html

@@ -136,6 +143,9 @@ endif

 	if [ -f install/dracut-install ]; then \

 		install -m 0755 install/dracut-install $(DESTDIR)$(pkglibdir)/dracut-install; \

 	fi

+	if [ -f skipcpio/skipcpio ]; then \

+		install -m 0755 skipcpio/skipcpio $(DESTDIR)$(pkglibdir)/skipcpio; \

+	fi

 	mkdir -p $(DESTDIR)${prefix}/lib/kernel/install.d

 	install -m 0755 50-dracut.install $(DESTDIR)${prefix}/lib/kernel/install.d/50-dracut.install

 	install -m 0755 51-dracut-rescue.install $(DESTDIR)${prefix}/lib/kernel/install.d/51-dracut-rescue.install

@@ -155,6 +165,7 @@ clean:

 	$(RM) dracut-*.rpm dracut-*.tar.bz2

 	$(RM) dracut-version.sh

 	$(RM) dracut-install install/dracut-install $(DRACUT_INSTALL_OBJECTS)

+	$(RM) skipcpio/skipcpio $(SKIPCPIO_OBJECTS)

 	$(RM) $(manpages) dracut.html

 	$(MAKE) -C test clean

diff --git a/skipcpio/skipcpio.c b/skipcpio/skipcpio.c

new file mode 100644

index 0000000..fbf391b

--- /dev/null

+++ b/skipcpio/skipcpio.c

@@ -0,0 +1,123 @@

+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/

+

+/* dracut-install.c  -- install files and executables

+

+   Copyright (C) 2012 Harald Hoyer

+   Copyright (C) 2012 Red Hat, Inc.  All rights reserved.

+

+   This program is free software: you can redistribute it and/or modify

+   under the terms of the GNU Lesser General Public License as published by

+   the Free Software Foundation; either version 2.1 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

+   Lesser General Public License for more details.

+

+   You should have received a copy of the GNU Lesser General Public License

+   along with this program; If not, see <http://www.gnu.org/licenses/>.

+*/

+

+#define PROGRAM_VERSION_STRING "1"

+

+#ifndef _GNU_SOURCE

+#define _GNU_SOURCE

+#endif

+

+#include <stdbool.h>

+#include <stdio.h>

+#include <stdlib.h>

+#include <unistd.h>

+#include <string.h>

+

+#define CPIO_END "TRAILER!!!"

+#define CPIO_ENDLEN (sizeof(CPIO_END)-1)

+

+static char buf[CPIO_ENDLEN * 2 + 1];

+

+int main(int argc, char **argv)

+{

+        FILE *f;

+        size_t s;

+        long pos = 0;

+

+        if (argc != 2) {

+                fprintf(stderr, "Usage: %s <file>\n", argv[0]);

+                exit(1);

+        }

+

+        f = fopen(argv[1], "r");

+

+        if (f == NULL) {

+                fprintf(stderr, "Cannot open file '%s'\n", argv[1]);

+                exit(1);

+        }

+

+        s = fread(buf, 6, 1, f);

+        if (s <= 0) {

+                fprintf(stderr, "Read error from file '%s'\n", argv[1]);

+                fclose(f);

+                exit(1);

+        }

+        fseek(f, 0, SEEK_SET);

+

+        /* check, if this is a cpio archive */

+        if ((buf[0] == 0x71 && buf[1] == 0xc7)

+            || (buf[0] == '0' && buf[1] == '7' && buf[0] == '0' && buf[1] == '7' && buf[0] == '0' && buf[1] == '1')) {

+

+                /* Search for CPIO_END */

+                do {

+                        char *h;

+                        fseek(f, pos, SEEK_SET);

+                        buf[sizeof(buf) - 1] = 0;

+                        s = fread(buf, CPIO_ENDLEN, 2, f);

+                        if (s <= 0)

+                                break;

+

+                        h = strstr(buf, CPIO_END);

+                        if (h) {

+                                pos = (h - buf) + pos + CPIO_ENDLEN;

+                                fseek(f, pos, SEEK_SET);

+                                break;

+                        }

+                        pos += CPIO_ENDLEN;

+                } while (!feof(f));

+

+                if (feof(f)) {

+                        /* CPIO_END not found, just cat the whole file */

+                        fseek(f, 0, SEEK_SET);

+                } else {

+                        /* skip zeros */

+                        while (!feof(f)) {

+                                size_t i;

+

+                                buf[sizeof(buf) - 1] = 0;

+                                s = fread(buf, 1, sizeof(buf) - 1, f);

+                                if (s <= 0)

+                                        break;

+

+                                for (i = 0; (i < s) && (buf[i] == 0); i++) ;

+

+                                if (buf[i] != 0) {

+                                        pos += i;

+                                        fseek(f, pos, SEEK_SET);

+                                        break;

+                                }

+

+                                pos += s;

+                        }

+                }

+        }

+        /* cat out the rest */

+        while (!feof(f)) {

+                s = fread(buf, 1, sizeof(buf), f);

+                if (s <= 0)

+                        break;

+

+                s = fwrite(buf, 1, s, stdout);

+                if (s <= 0)

+                        break;

+        }

+        fclose(f);

+}