From 8687974a09430df54a9424775ddd131cc270794b Mon Sep 17 00:00:00 2001
From: Deon George <deon@leenooks.net>
Date: Sat, 28 May 2022 11:42:25 +1000
Subject: [PATCH] Feature main/sbbs#404 - Reserve space (up to tagsBuffer) so
 that headers can be modified, and tags can be added up to tagsBuffer in size

---
 src/smblib/smblib.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/src/smblib/smblib.c b/src/smblib/smblib.c
index 53b886392..29624a79a 100644
--- a/src/smblib/smblib.c
+++ b/src/smblib/smblib.c
@@ -1603,6 +1603,7 @@ int smb_addmsghdr(smb_t* smb, smbmsg_t* msg, int storage)
 	ulong	hdrlen;
 	off_t	idxlen;
 	size_t	idxreclen = smb_idxreclen(smb);
+	int	tagsBuffer = 4; /* @todo this should be determined from a system configuration item */
 
 	if(smb->shd_fp==NULL) {
 		safe_snprintf(smb->last_error,sizeof(smb->last_error),"%s msgbase not open", __FUNCTION__);
@@ -1612,6 +1613,26 @@ int smb_addmsghdr(smb_t* smb, smbmsg_t* msg, int storage)
 	if(!smb->locked && smb_locksmbhdr(smb)!=SMB_SUCCESS)
 		return(SMB_ERR_LOCK);
 
+	/* Add a tags buffer if a tag doesnt exist. */
+	if (tagsBuffer) {
+		int hasTags = 0;
+
+		for(i=0;i<msg->total_hfields;i++) {
+			if (msg->hfield[i].type == SMB_TAGS) {
+				hasTags = 1;
+				break;
+			}
+		}
+		if (! hasTags) {
+			if (i=smb_hfield_add(msg,SMB_TAGS,tagsBuffer,"",TRUE) != SMB_SUCCESS) {
+				safe_snprintf(smb->last_error,sizeof(smb->last_error)
+					,"%s error adding padding for TAG field", __FUNCTION__);
+				smb_unlocksmbhdr(smb);
+				return(i);
+			}
+		}
+	}
+
 	hdrlen=smb_getmsghdrlen(msg);
 	if(hdrlen>SMB_MAX_HDR_LEN) { /* headers are limited to 64k in size */
 		smb_unlocksmbhdr(smb);
-- 
2.31.1