1 files changed, 92 insertions, 0 deletions
diff --git a/rpm2cpio.c b/rpm2cpio.c
new file mode 100644
index 0000000..8d4ca84
--- /dev/null
+++ b/rpm2cpio.c
@@ -0,0 +1,92 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Mini rpm2cpio implementation for busybox
+ *
+ * Copyright (C) 2001 by Laurence Anderson
+ *
+ * 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include "busybox.h"
+#include <netinet/in.h> /* For ntohl & htonl function */
+#include <string.h>
+
+#define RPM_MAGIC "\355\253\356\333"
+#define RPM_HEADER_MAGIC "\216\255\350"
+
+typedef unsigned char u8;
+typedef unsigned short u16;
+typedef unsigned int u32;
+
+struct rpm_lead {
+    unsigned char magic[4];
+    u8 major, minor;
+    u16 type;
+    u16 archnum;
+    char name[66];
+    u16 osnum;
+    u16 signature_type;
+    char reserved[16];
+};
+
+struct rpm_header {
+	char magic[3]; /* 3 byte magic: 0x8e 0xad 0xe8 */
+	u8 version; /* 1 byte version number */
+	u32 reserved; /* 4 bytes reserved */
+	u32 entries; /* Number of entries in header (4 bytes) */
+	u32 size; /* Size of store (4 bytes) */
+};
+
+void skip_header(FILE *rpmfile)
+{
+	struct rpm_header header;
+
+	fread(&header, sizeof(struct rpm_header), 1, rpmfile);
+	if (strncmp((char *) &header.magic, RPM_HEADER_MAGIC, 3) != 0) error_msg_and_die("Invalid RPM header magic"); /* Invalid magic */
+	if (header.version != 1) error_msg_and_die("Unsupported RPM header version"); /* This program only supports v1 headers */
+	header.entries = ntohl(header.entries);
+	header.size = ntohl(header.size);
+	fseek (rpmfile, 16 * header.entries, SEEK_CUR); /* Seek past index entries */
+	fseek (rpmfile, header.size, SEEK_CUR); /* Seek past store */
+}
+
+/* No getopt required */
+extern int rpm2cpio_main(int argc, char **argv)
+{
+	struct rpm_lead lead;
+	int gunzip_pid;
+	FILE *rpmfile, *cpiofile;
+
+	if (argc == 1) {
+		rpmfile = stdin;
+	} else {
+		rpmfile = fopen(argv[1], "r");
+	 	if (!rpmfile) perror_msg_and_die("Can't open rpm file");
+	}
+
+	fread (&lead, sizeof(struct rpm_lead), 1, rpmfile);
+	if (strncmp((char *) &lead.magic, RPM_MAGIC, 4) != 0) error_msg_and_die("Invalid RPM magic"); /* Just check the magic, the rest is irrelevant */
+	/* Skip the signature header */
+	skip_header(rpmfile);
+	fseek(rpmfile, (8 - (ftell(rpmfile) % 8)) % 8, SEEK_CUR); /* Pad to 8 byte boundary */
+	/* Skip the main header */
+	skip_header(rpmfile);
+
+	cpiofile = gz_open(rpmfile, &gunzip_pid);
+	copyfd(fileno(cpiofile), fileno(stdout));
+	gz_close(gunzip_pid);
+	fclose(rpmfile);
+	return 0;
+}