From: Tim Kientzle <kientzle@acm.org>
Date: Mon, 10 Aug 2026 13:58:16 +0000 (-0700)
Subject: Merge pull request #3321 from carrerasdarren-cell/fix/cpio-newc-inode-synthesis
X-Git-Url: http://git.ipfire.org/index.cgi?a=commitdiff_plain;p=thirdparty%2Flibarchive.git

Merge pull request #3321 from carrerasdarren-cell/fix/cpio-newc-inode-synthesis

cpio: synthesize newc inode values
---

6ea9e10bc535dfb22807319d0d7f2e1d921599e8
diff --cc libarchive/archive_write_set_format_cpio_newc.c
index 069dbc184,710a68659..9f6c88edd
--- a/libarchive/archive_write_set_format_cpio_newc.c
+++ b/libarchive/archive_write_set_format_cpio_newc.c
@@@ -138,10 -150,110 +150,90 @@@ archive_write_newc_options(struct archi
      const char *val)
  {
  	struct cpio *cpio = a->format_data;
 -	int ret = ARCHIVE_FAILED;
 -
 -	if (strcmp(key, "hdrcharset")  == 0) {
 -		if (val == NULL || val[0] == 0)
 -			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
 -			    "%s: hdrcharset option needs a character-set name",
 -			    a->format_name);
 -		else {
 -			cpio->opt_sconv = archive_string_conversion_to_charset(
 -			    &a->archive, val, 0);
 -			if (cpio->opt_sconv != NULL)
 -				ret = ARCHIVE_OK;
 -			else
 -				ret = ARCHIVE_FATAL;
 -		}
 -		return (ret);
 -	}
 -
 -	/* Note: The "warn" return is just to inform the options
 -	 * supervisor that we didn't handle it.  It will generate
 -	 * a suitable error if no one used this option. */
 -	return (ARCHIVE_WARN);
 +	return (__archive_write_option_header_charset(a, key, val,
 +	    &cpio->opt_sconv));
  }
  
+ /*
+  * The newc format stores 32-bit inode numbers and relies on them to identify
+  * hardlinked files. Generate unique in-range values so distinct 64-bit inode
+  * numbers cannot collide when written to the archive.
+  */
+ static int64_t
+ synthesize_ino_value(struct archive_write *a, struct archive_entry *entry)
+ {
+ 	struct cpio *cpio = a->format_data;
+ 	int64_t devmajor = archive_entry_devmajor(entry);
+ 	int64_t devminor = archive_entry_devminor(entry);
+ 	int64_t ino = archive_entry_ino64(entry);
+ 	int64_t ino_new;
+ 	size_t i;
+ 
+ 	if (ino == 0)
+ 		return (0);
+ 
+ 	/* Directory link counts do not represent separate archive entries. */
+ 	if (archive_entry_nlink(entry) < 2 ||
+ 	    archive_entry_filetype(entry) == AE_IFDIR) {
+ 		if (cpio->ino_next == UINT32_MAX) {
+ 			archive_set_error(&a->archive, ERANGE,
+ 			    "No available inode values for cpio format");
+ 			return (ARCHIVE_FATAL);
+ 		}
+ 		return (++cpio->ino_next);
+ 	}
+ 
+ 	/* TODO: Revisit the flat list if large hardlink sets become slow. */
+ 	for (i = 0; i < cpio->ino_list_next; ++i) {
+ 		if (cpio->ino_list[i].old_devmajor == devmajor &&
+ 		    cpio->ino_list[i].old_devminor == devminor &&
+ 		    cpio->ino_list[i].old_ino == ino)
+ 			return (cpio->ino_list[i].new_ino);
+ 	}
+ 
+ 	if (cpio->ino_next == UINT32_MAX) {
+ 		archive_set_error(&a->archive, ERANGE,
+ 		    "No available inode values for cpio format");
+ 		return (ARCHIVE_FATAL);
+ 	}
+ 	ino_new = ++cpio->ino_next;
+ 
+ 	if (cpio->ino_list_size <= cpio->ino_list_next) {
+ 		size_t newsize, size;
+ 
+ 		if (cpio->ino_list_size < 512)
+ 			newsize = 512;
+ 		else if (archive_ckd_mul_size(&newsize,
+ 		    cpio->ino_list_size, 2)) {
+ 			archive_set_error(&a->archive, ENOMEM,
+ 			    "No memory for inode translation table");
+ 			return (ARCHIVE_FATAL);
+ 		}
+ 		if (archive_ckd_mul_size(&size,
+ 		    newsize, sizeof(cpio->ino_list[0]))) {
+ 			archive_set_error(&a->archive, ENOMEM,
+ 			    "No memory for inode translation table");
+ 			return (ARCHIVE_FATAL);
+ 		}
+ 		void *newlist = realloc(cpio->ino_list, size);
+ 		if (newlist == NULL) {
+ 			archive_set_error(&a->archive, ENOMEM,
+ 			    "No memory for inode translation table");
+ 			return (ARCHIVE_FATAL);
+ 		}
+ 
+ 		cpio->ino_list_size = newsize;
+ 		cpio->ino_list = newlist;
+ 	}
+ 
+ 	cpio->ino_list[cpio->ino_list_next].old_devmajor = devmajor;
+ 	cpio->ino_list[cpio->ino_list_next].old_devminor = devminor;
+ 	cpio->ino_list[cpio->ino_list_next].old_ino = ino;
+ 	cpio->ino_list[cpio->ino_list_next].new_ino = ino_new;
+ 	++cpio->ino_list_next;
+ 	return (ino_new);
+ }
+ 
  static struct archive_string_conv *
  get_sconv(struct archive_write *a)
  {