Attachment 17070 Details for Bug 14928 – git-am fix for master.

[patch] git-am fix for master.

0001-s3-smbd-Create-and-use-a-common-function-for-generat.patch (text/plain), 4.17 KB, created by Jeremy Allison on 2022-01-05 20:04:31 UTC

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Creator: Jeremy Allison

Created: 2022-01-05 20:04:31 UTC

Size: 4.17 KB

patch

obsolete

>From 4fc4efeb6afd9dcf2661df8a5b01ee1dc112d822 Mon Sep 17 00:00:00 2001
>From: Jeremy Allison <jra@samba.org>
>Date: Wed, 5 Jan 2022 11:40:46 -0800
>Subject: [PATCH] s3: smbd: Create and use a common function for generating a
> fileid - create_clock_itime().
>
>This first gets the clock_gettime_mono() value, converts to an NTTIME (as
>this is what is stored in the dos attribute EA), then mixes in 8 bits of
>randomness shifted up by 55 bits to cope with poor resolution clocks to
>avoid duplicate inodes.
>
>Using 8 bits of randomness on top of an NTTIME gives us around 114
>years headroom.
>
>The top bit is then set to avoid collisions with system inode
>numbers.
>
>BUG: https://bugzilla.samba.org/show_bug.cgi?id=14928
>
>Signed-off-by: Jeremy Allison <jra@samba.org>
>---
> source3/include/proto.h |  1 +
> source3/lib/system.c    | 43 +++++++++++++++++++++++++++++++++++++++++
> source3/smbd/open.c     |  6 +++---
> 3 files changed, 47 insertions(+), 3 deletions(-)
>
>diff --git a/source3/include/proto.h b/source3/include/proto.h
>index 6154b1ab26d..dba728b3d86 100644
>--- a/source3/include/proto.h
>+++ b/source3/include/proto.h
>@@ -175,6 +175,7 @@ void update_stat_ex_create_time(struct stat_ex *dst, struct timespec create_time
> void update_stat_ex_file_id(struct stat_ex *dst, uint64_t file_id);
> void update_stat_ex_from_saved_stat(struct stat_ex *dst,
> 				    const struct stat_ex *src);
>+void create_clock_itime(struct stat_ex *dst);
> int sys_stat(const char *fname, SMB_STRUCT_STAT *sbuf,
> 	     bool fake_dir_create_times);
> int sys_fstat(int fd, SMB_STRUCT_STAT *sbuf,
>diff --git a/source3/lib/system.c b/source3/lib/system.c
>index 671fc2760a0..9f62748a3f7 100644
>--- a/source3/lib/system.c
>+++ b/source3/lib/system.c
>@@ -310,6 +310,49 @@ void init_stat_ex_from_stat (struct stat_ex *dst,
> 	dst->st_ex_iflags |= ST_EX_IFLAG_CALCULATED_FILE_ID;
> }
> 
>+/*******************************************************************
>+ Create a clock-derived itime (imaginary) birthtime.
>+********************************************************************/
>+
>+void create_clock_itime(struct stat_ex *dst)
>+{
>+	NTTIME tval;
>+	struct timespec itime;
>+	uint64_t mixin;
>+	uint8_t rval;
>+
>+	/* Start with the system clock. */
>+	clock_gettime_mono(&itime);
>+
>+	/* Convert to NTTIME. */
>+	tval = unix_timespec_to_nt_time(itime);
>+
>+	/* Generate a random byte. */
>+	generate_random_buffer((unsigned char *)&rval, 1);
>+	mixin = rval;
>+
>+	/*
>+	 * Shift up by 55 bits. This gives us 114 years
>+	 * of headroom.
>+	 */
>+	mixin <<= 55;
>+
>+	/*
>+	 * Set the top bit to differentiate this
>+	 * from a system inode.
>+	 */
>+	mixin |= 0x8000000000000000LL;
>+
>+	/* And OR into the nttime. */
>+	tval |= mixin;
>+
>+	/* Convert back to a timespec. */
>+	itime = nt_time_to_full_timespec(tval);
>+
>+	/* And set as a generated itime. */
>+	update_stat_ex_itime(dst, itime);
>+}
>+
> /*******************************************************************
> A stat() wrapper.
> ********************************************************************/
>diff --git a/source3/smbd/open.c b/source3/smbd/open.c
>index e3bb304292e..cf5c620fe21 100644
>--- a/source3/smbd/open.c
>+++ b/source3/smbd/open.c
>@@ -4129,13 +4129,13 @@ static NTSTATUS open_file_ntcreate(connection_struct *conn,
> 	 * If we created a file and it's not a stream, this is the point where
> 	 * we set the itime (aka invented time) that get's stored in the DOS
> 	 * attribute xattr. The value is going to be either what the filesystem
>-	 * provided or a copy of the creation date.
>+	 * provided or a generated itime value.
> 	 *
> 	 * Either way, we turn the itime into a File-ID, unless the filesystem
> 	 * provided one (unlikely).
> 	 */
> 	if (info == FILE_WAS_CREATED && !is_named_stream(smb_fname)) {
>-		smb_fname->st.st_ex_iflags &= ~ST_EX_IFLAG_CALCULATED_ITIME;
>+		create_clock_itime(&smb_fname->st);
> 
> 		if (lp_store_dos_attributes(SNUM(conn)) &&
> 		    smb_fname->st.st_ex_iflags & ST_EX_IFLAG_CALCULATED_FILE_ID)
>@@ -4317,7 +4317,7 @@ static NTSTATUS mkdir_internal(connection_struct *conn,
> 		return NT_STATUS_NOT_A_DIRECTORY;
> 	}
> 
>-	smb_dname->st.st_ex_iflags &= ~ST_EX_IFLAG_CALCULATED_ITIME;
>+	create_clock_itime(&smb_dname->st);
> 
> 	if (lp_store_dos_attributes(SNUM(conn))) {
> 		if (smb_dname->st.st_ex_iflags & ST_EX_IFLAG_CALCULATED_FILE_ID)
>-- 
>2.30.2
>

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