embox

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/**
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 * @file
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 * @brief CPIO file format.
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 *
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 * @date 29.09.10
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 * @author Nikolay Korotky
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 * @author Eldar Abusalimov
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 *          - Rewrite from scratch, no more dependencies on initfs.
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 */
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#include <cpio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <stdio.h>
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#include <sys/stat.h>
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#include <fs/fs_driver.h>
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#include <kernel/printk.h>
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/**
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 * The pathname is followed by NUL bytes so that the total size of the fixed
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 * header plus pathname is a multiple of four. Likewise, the file data is
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 * padded to a multiple of four bytes.
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 */
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#define NEWC_NAME_ALIGN(len) ((((len) + 1) & ~3) + 2)
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#define NEWC_FILE_ALIGN(len) (((len) + 3) & ~3)
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/* Value for the field `c_magic'.  */
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#define NEWC_MAGIC       "070701"
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#define OLD_BIN_MAGIC    "070707"
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#define NEWC_FIELD_SZ     8
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/* New ASCII Format */
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struct newc_hdr {
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	char c_magic[sizeof(NEWC_MAGIC) - 1]; /**< Must be "070701". */
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	char c_ino[NEWC_FIELD_SZ];       /**< The inode numbers from the disk. */
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	char c_mode[NEWC_FIELD_SZ];      /**< Permissions and the file type.*/
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	char c_uid[NEWC_FIELD_SZ];       /**< User id of the owner. */
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	char c_gid[NEWC_FIELD_SZ];       /**< Group id of the owner. */
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	char c_nlink[NEWC_FIELD_SZ];     /**< The number of links to this file.*/
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	char c_mtime[NEWC_FIELD_SZ];     /**< Modification time, seconds. */
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	char c_filesize[NEWC_FIELD_SZ];  /**< Zero for FIFOs and directories. */
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	char c_devmajor[NEWC_FIELD_SZ];
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	char c_devminor[NEWC_FIELD_SZ];
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	char c_rdevmajor[NEWC_FIELD_SZ];
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	char c_rdevminor[NEWC_FIELD_SZ];
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	char c_namesize[NEWC_FIELD_SZ];  /**< Bytes in the pathname.*/
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	char c_check[NEWC_FIELD_SZ];     /**< Ignored, must be zero. */
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};
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struct newc_hdr_parsed {
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	unsigned long ino;
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	unsigned long mode;
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	unsigned long uid;
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	unsigned long gid;
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	unsigned long nlink;
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	unsigned long mtime;
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	unsigned long filesize;
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	unsigned long devmajor;
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	unsigned long devminor;
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	unsigned long rdevmajor;
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	unsigned long rdevminor;
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	unsigned long namesize;
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};
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#define STR_LEN_TUPLE(str) (str), (sizeof(str) - 1)
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static char *cpio_parse_newc(const struct newc_hdr *hdr,
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		struct cpio_entry *entry) {
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	char *raw = (char *) hdr + sizeof(hdr->c_magic);
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	struct newc_hdr_parsed parsed;
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	char field_buff[NEWC_FIELD_SZ + 1];
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	field_buff[NEWC_FIELD_SZ] = '\0';
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	for (unsigned long *p_field = (unsigned long *) &parsed;
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	     p_field < (unsigned long *) (&parsed + 1);
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	     ++p_field, raw += NEWC_FIELD_SZ) {
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		unsigned long tmp;
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		memcpy(field_buff, raw, NEWC_FIELD_SZ);
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		tmp = strtol(field_buff, NULL, 16);
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		memcpy(p_field, &tmp, sizeof *p_field);
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	}
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	raw += NEWC_FIELD_SZ; /* skip c_check field, now raw points to name. */
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	if (strncmp(raw, STR_LEN_TUPLE("TRAILER!!!")) == 0) {
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		return NULL;
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	}
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	entry->mode  = parsed.mode;
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	entry->uid   = parsed.uid;
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	entry->gid   = parsed.gid;
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	entry->mtime = parsed.mtime;
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#if 0
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	entry->ino   = parsed.ino;
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	entry->nlink = parsed.nlink;
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	entry->devmajor = parsed.devmajor;
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	entry->devminor = parsed.devminor;
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	entry->rdevmajor = parsed.rdevmajor;
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	entry->rdevminor = parsed.rdevminor;
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#endif
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	entry->name = raw;
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	entry->name_len = parsed.namesize;
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	raw += NEWC_NAME_ALIGN(parsed.namesize);
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	entry->data = raw;
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	entry->size = parsed.filesize;
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	raw += NEWC_FILE_ALIGN(parsed.filesize);
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	return raw;
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}
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char *cpio_parse_entry(const char *cpio, struct cpio_entry *entry) {
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	if (memcmp(cpio, STR_LEN_TUPLE(OLD_BIN_MAGIC)) == 0) {
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		printk("Use -H newc option for create CPIO archive\n");
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		return NULL;
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	}
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	if (memcmp(cpio, STR_LEN_TUPLE(NEWC_MAGIC)) != 0) {
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		printk("Newc ASCII CPIO format not recognized\n");
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		return NULL;
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	}
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	return cpio_parse_newc((struct newc_hdr *) cpio, entry);
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}
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