makefs: Make cd9660 Rock Ridge inodes reproducible

Rock Ridge extensions include an inode field:

    "POSIX File Serial Number" shall have the same meaning as and may be
    used for the st_ino field of POSIX:5.6.1. This field shall be
    recorded according to ISO 9660:7.3.3. Directory Records which share
    the value of this field are defined as links (see POSIX:2.2.2.17)
    and, by definition, point to the same file or directory.

Previously we'd store the source file's st_ino (except that in metalog
mode we'd record 0 for files with nlink = 1).  This had two issues: the
generated ISO image was nonreproducible due to the arbitrary inode
numbers, and files without hard links would falsely be detected (by
certain tools) as hard links to each other.

Note that the kernel's cd9660(5) file system ignores the Rock Ridge
PX File Serial Number, so this issue isn't observed by mounting such a
file system.

Instead of using the source inode directly, assign target inode numbers
sequentially.  Use a map so that files with the same source inode (hard
links) still receive the same target inode number.

PR:		284795
PR:		285027
Reviewed by:	brooks
Sponsored by:	The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D49141

(cherry picked from commit 518cdd344ec51584478f39b9a9cac77fc0766ce1)
(cherry picked from commit 337f5e7a44c4d5ac29e0b0c0fe957bb3b9bae222)
(cherry picked from commit a18be39aafc1b55fd67603ee6a6d820d0fcd877f)

usr.sbin/makefs/cd9660.h

@@ -51,6 +51,7 @@
 #include <sys/queue.h>
 #include <sys/param.h>
 #include <sys/endian.h>
+#include <sys/tree.h>
 
 #include "makefs.h"
 #include "iso.h"
@@ -203,6 +204,12 @@ typedef struct _volume_descriptor
 	struct _volume_descriptor *next;
 } volume_descriptor;
 
+struct inode_map_node {
+	RB_ENTRY(inode_map_node) entry;
+	uint64_t key;
+	uint64_t value;
+};
+
 typedef struct _iso9660_disk {
 	int sectorSize;
 	struct iso_primary_descriptor		primaryDescriptor;
@@ -249,7 +256,11 @@ typedef struct _iso9660_disk {
 	unsigned rock_ridge_move_count;
 	cd9660node *rr_moved_dir;
 
+	uint64_t rr_inode_next;
+	RB_HEAD(inode_map_tree, inode_map_node) rr_inode_map;
+
 	int archimedes_enabled;
+
 	int chrp_boot;
 
 	/* Spec breaking options */
@@ -276,6 +287,8 @@ typedef struct _iso9660_disk {
 
 } iso9660_disk;
 
+RB_PROTOTYPE(inode_map_tree, inode_map_node, entry, inode_map_node_cmp);
+
 /************ FUNCTIONS **************/
 int			cd9660_valid_a_chars(const char *);
 int			cd9660_valid_d_chars(const char *);

usr.sbin/makefs/cd9660/iso9660_rrip.c

@@ -47,7 +47,7 @@
 #include "iso9660_rrip.h"
 #include <util.h>
 
-static void cd9660_rrip_initialize_inode(cd9660node *);
+static void cd9660_rrip_initialize_inode(iso9660_disk *, cd9660node *);
 static int cd9660_susp_handle_continuation(iso9660_disk *, cd9660node *);
 static int cd9660_susp_handle_continuation_common(iso9660_disk *, cd9660node *,
     int);
@@ -70,6 +70,11 @@ cd9660_susp_initialize(iso9660_disk *diskStructure, cd9660node *node,
 	if (node->dot_dot_record != 0)
 		TAILQ_INIT(&(node->dot_dot_record->head));
 
+	if (diskStructure->rr_inode_next == 0) {
+		RB_INIT(&diskStructure->rr_inode_map);
+		diskStructure->rr_inode_next = 1;
+	}
+
 	 /* SUSP specific entries here */
 	if ((r = cd9660_susp_initialize_node(diskStructure, node)) < 0)
 		return r;
@@ -101,6 +106,7 @@ int
 cd9660_susp_finalize(iso9660_disk *diskStructure, cd9660node *node)
 {
 	cd9660node *temp;
+	struct inode_map_node *mapnode, *mapnodetmp;
 	int r;
 
 	assert(node != NULL);
@@ -117,6 +123,16 @@ cd9660_susp_finalize(iso9660_disk *diskStructure, cd9660node *node)
 		if ((r = cd9660_susp_finalize(diskStructure, temp)) < 0)
 			return r;
 	}
+
+	if (diskStructure->rr_inode_next != 0) {
+		RB_FOREACH_SAFE(mapnode, inode_map_tree,
+		    &(diskStructure->rr_inode_map), mapnodetmp) {
+			RB_REMOVE(inode_map_tree,
+			    &(diskStructure->rr_inode_map), mapnode);
+			free(mapnode);
+		}
+		diskStructure->rr_inode_next = 0;
+	}
 	return 1;
 }
 
@@ -323,7 +339,7 @@ cd9660_susp_initialize_node(iso9660_disk *diskStructure, cd9660node *node)
 }
 
 static void
-cd9660_rrip_initialize_inode(cd9660node *node)
+cd9660_rrip_initialize_inode(iso9660_disk *diskStructure, cd9660node *node)
 {
 	struct ISO_SUSP_ATTRIBUTES *attr;
 
@@ -337,7 +353,7 @@ cd9660_rrip_initialize_inode(cd9660node *node)
 		/* PX - POSIX attributes */
 		attr = cd9660node_susp_create_node(SUSP_TYPE_RRIP,
 			SUSP_ENTRY_RRIP_PX, "PX", SUSP_LOC_ENTRY);
-		cd9660node_rrip_px(attr, node->node);
+		cd9660node_rrip_px(diskStructure, attr, node->node);
 
 		TAILQ_INSERT_TAIL(&node->head, attr, rr_ll);
 
@@ -390,7 +406,8 @@ cd9660_rrip_initialize_node(iso9660_disk *diskStructure, cd9660node *node,
 			/* PX - POSIX attributes */
 			current = cd9660node_susp_create_node(SUSP_TYPE_RRIP,
 				SUSP_ENTRY_RRIP_PX, "PX", SUSP_LOC_ENTRY);
-			cd9660node_rrip_px(current, parent->node);
+			cd9660node_rrip_px(diskStructure, current,
+			    parent->node);
 			TAILQ_INSERT_TAIL(&node->head, current, rr_ll);
 
 			/* TF - timestamp */
@@ -405,7 +422,8 @@ cd9660_rrip_initialize_node(iso9660_disk *diskStructure, cd9660node *node,
 			/* PX - POSIX attributes */
 			current = cd9660node_susp_create_node(SUSP_TYPE_RRIP,
 				SUSP_ENTRY_RRIP_PX, "PX", SUSP_LOC_ENTRY);
-			cd9660node_rrip_px(current, grandparent->node);
+			cd9660node_rrip_px(diskStructure, current,
+			    grandparent->node);
 			TAILQ_INSERT_TAIL(&node->head, current, rr_ll);
 
 			/* TF - timestamp */
@@ -422,7 +440,7 @@ cd9660_rrip_initialize_node(iso9660_disk *diskStructure, cd9660node *node,
 			TAILQ_INSERT_TAIL(&node->head, current, rr_ll);
 		}
 	} else {
-		cd9660_rrip_initialize_inode(node);
+		cd9660_rrip_initialize_inode(diskStructure, node);
 
 		if (node == diskStructure->rr_moved_dir) {
 			cd9660_rrip_add_NM(node, RRIP_DEFAULT_MOVE_DIR_NAME);
@@ -630,8 +648,45 @@ cd9660_createSL(cd9660node *node)
 	}
 }
 
+static int
+inode_map_node_cmp(struct inode_map_node *a, struct inode_map_node *b)
+{
+	if (a->key < b->key)
+		return (-1);
+	if (a->key > b->key)
+		return (1);
+	return (0);
+}
+
+RB_GENERATE(inode_map_tree, inode_map_node, entry, inode_map_node_cmp);
+
+static uint64_t
+inode_map(iso9660_disk *diskStructure, uint64_t in)
+{
+	struct inode_map_node lookup = { .key = in };
+	struct inode_map_node *node;
+
+	/*
+	 * Always assign an inode number if src inode unset.  mtree mode leaves
+	 * src inode unset for files with st_nlink == 1.
+	 */
+	if (in != 0) {
+		node = RB_FIND(inode_map_tree, &(diskStructure->rr_inode_map),
+		    &lookup);
+		if (node != NULL)
+			return (node->value);
+	}
+
+	node = emalloc(sizeof(struct inode_map_node));
+	node->key = in;
+	node->value = diskStructure->rr_inode_next++;
+	RB_INSERT(inode_map_tree, &(diskStructure->rr_inode_map), node);
+	return (node->value);
+}
+
 int
-cd9660node_rrip_px(struct ISO_SUSP_ATTRIBUTES *v, fsnode *pxinfo)
+cd9660node_rrip_px(iso9660_disk *diskStructure, struct ISO_SUSP_ATTRIBUTES *v,
+    fsnode *pxinfo)
 {
 	v->attr.rr_entry.PX.h.length[0] = 44;
 	v->attr.rr_entry.PX.h.version[0] = 1;
@@ -643,8 +698,8 @@ cd9660node_rrip_px(struct ISO_SUSP_ATTRIBUTES *v, fsnode *pxinfo)
 	    v->attr.rr_entry.PX.uid);
 	cd9660_bothendian_dword(pxinfo->inode->st.st_gid,
 	    v->attr.rr_entry.PX.gid);
-	cd9660_bothendian_dword(pxinfo->inode->st.st_ino,
-	    v->attr.rr_entry.PX.serial);
+	cd9660_bothendian_dword(inode_map(diskStructure,
+	    pxinfo->inode->st.st_ino), v->attr.rr_entry.PX.serial);
 
 	return 1;
 }

usr.sbin/makefs/cd9660/iso9660_rrip.h

@@ -224,7 +224,7 @@ int cd9660_susp_finalize_node(iso9660_disk *, cd9660node *);
 int cd9660_rrip_finalize_node(cd9660node *);
 
 /* POSIX File attribute */
-int cd9660node_rrip_px(struct ISO_SUSP_ATTRIBUTES *, fsnode *);
+int cd9660node_rrip_px(iso9660_disk *, struct ISO_SUSP_ATTRIBUTES *, fsnode *);
 
 /* Device number */
 int cd9660node_rrip_pn(struct ISO_SUSP_ATTRIBUTES *, fsnode *);