Attachment 10635 Details for Bug 10123 – fix for 3-6-stable branch, modified from master - just in case it's useful to others maintaining the 3.6 series

[patch] fix for 3-6-stable branch, modified from master - just in case it's useful to others maintaining the 3.6 series

0001-libsmb-reuse-connections-derived-from-DFS-referrals_36s.patch (text/plain), 6.48 KB, created by David Disseldorp on 2015-01-19 16:27:00 UTC

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Creator: David Disseldorp

Created: 2015-01-19 16:27:00 UTC

Size: 6.48 KB

patch

obsolete

>From a3e4041e2419469546bebde1ab2cb202c15be16e Mon Sep 17 00:00:00 2001
>From: David Disseldorp <ddiss@samba.org>
>Date: Fri, 16 Jan 2015 16:21:22 +0100
>Subject: [PATCH] libsmb: reuse connections derived from DFS referrals
>
>[MS-DFSC] 3.2.1.1 and 3.2.1.2 states that DFS targets with the same site
>location or relative cost are placed in random order in a DFS referral
>response.
>
>libsmbclient currently resolves DFS referrals on every API call, always
>using the first entry in the referral response. With random ordering,
>libsmbclient may open a new server connection, rather than reuse an
>existing (cached) connection established in a previous DFS referred API
>call.
>
>This change sees libsmbclient check the connection cache for any of the
>DFS referral response entries before creating a new connection.
>
>This change is based on a patch by Har Gagan Sahai
><SHarGagan@novell.com>.
>
>Bug: https://bugzilla.samba.org/show_bug.cgi?id=10123
>
>Signed-off-by: David Disseldorp <ddiss@samba.org>
>Reviewed-by: Jeremy Allison <jra@samba.org>
>(cherry picked from commit 7b7d4f740fe5017107d3100041cc8c7982f0eac7)
>[ddiss@samba.org: 3.6 rebase without smbXcli_tcon or ntstatus return]
>---
> source3/libsmb/clidfs.c | 97 ++++++++++++++++++++++++++++++++++++++-----------
> 1 file changed, 76 insertions(+), 21 deletions(-)
>
>diff --git a/source3/libsmb/clidfs.c b/source3/libsmb/clidfs.c
>index 23e1471..1d4b6be 100644
>--- a/source3/libsmb/clidfs.c
>+++ b/source3/libsmb/clidfs.c
>@@ -767,6 +767,11 @@ NTSTATUS cli_dfs_get_referral(TALLOC_CTX *ctx,
> 
> /********************************************************************
> ********************************************************************/
>+struct cli_dfs_path_split {
>+	char *server;
>+	char *share;
>+	char *extrapath;
>+};
> 
> bool cli_resolve_path(TALLOC_CTX *ctx,
> 			const char *mountpt,
>@@ -784,15 +789,16 @@ bool cli_resolve_path(TALLOC_CTX *ctx,
> 	char *cleanpath = NULL;
> 	char *extrapath = NULL;
> 	int pathlen;
>-	char *server = NULL;
>-	char *share = NULL;
> 	struct cli_state *newcli = NULL;
>+	struct cli_state *ccli = NULL;
>+	int count = 0;
> 	char *newpath = NULL;
> 	char *newmount = NULL;
> 	char *ppath = NULL;
> 	SMB_STRUCT_STAT sbuf;
> 	uint32 attributes;
> 	NTSTATUS status;
>+	struct cli_dfs_path_split *dfs_refs = NULL;
> 
> 	if ( !rootcli || !path || !targetcli ) {
> 		return false;
>@@ -874,13 +880,67 @@ bool cli_resolve_path(TALLOC_CTX *ctx,
> 		return false;
> 	}
> 
>-	/* Just store the first referral for now. */
>-
> 	if (!refs[0].dfspath) {
> 		return false;
> 	}
>-	if (!split_dfs_path(ctx, refs[0].dfspath, &server, &share,
>-			    &extrapath)) {
>+
>+	/*
>+	 * Bug#10123 - DFS referal entries can be provided in a random order,
>+	 * so check the connection cache for each item to avoid unnecessary
>+	 * reconnections.
>+	 */
>+	dfs_refs = talloc_array(ctx, struct cli_dfs_path_split, num_refs);
>+	if (dfs_refs == NULL) {
>+		return false;
>+	}
>+
>+	for (count = 0; count < num_refs; count++) {
>+		if (!split_dfs_path(dfs_refs, refs[count].dfspath,
>+				    &dfs_refs[count].server,
>+				    &dfs_refs[count].share,
>+				    &dfs_refs[count].extrapath)) {
>+			TALLOC_FREE(dfs_refs);
>+			return false;
>+		}
>+
>+		ccli = cli_cm_find(rootcli, dfs_refs[count].server,
>+				   dfs_refs[count].share);
>+		if (ccli != NULL) {
>+			extrapath = dfs_refs[count].extrapath;
>+			*targetcli = ccli;
>+			break;
>+		}
>+	}
>+
>+	/*
>+	 * If no cached connection was found, then connect to the first live
>+	 * referral server in the list.
>+	 */
>+	for (count = 0; (ccli == NULL) && (count < num_refs); count++) {
>+		/* Connect to the target server & share */
>+		*targetcli = cli_cm_connect(ctx, rootcli,
>+				dfs_refs[count].server,
>+				dfs_refs[count].share,
>+				dfs_auth_info,
>+				false,
>+				(rootcli->trans_enc_state != NULL),
>+				rootcli->protocol,
>+				0,
>+				0x20);
>+		if (*targetcli == NULL) {
>+			d_printf("Unable to follow dfs referral [\\%s\\%s]\n",
>+				 dfs_refs[count].server,
>+				 dfs_refs[count].share);
>+			continue;
>+		} else {
>+			extrapath = dfs_refs[count].extrapath;
>+			break;
>+		}
>+	}
>+
>+	/* No available referral server for the connection */
>+	if (*targetcli == NULL) {
>+		TALLOC_FREE(dfs_refs);
> 		return false;
> 	}
> 
>@@ -888,12 +948,14 @@ bool cli_resolve_path(TALLOC_CTX *ctx,
> 
> 	dfs_path = cli_dfs_make_full_path(ctx, rootcli, path);
> 	if (!dfs_path) {
>+		TALLOC_FREE(dfs_refs);
> 		return false;
> 	}
> 	pathlen = strlen(dfs_path);
> 	consumed = MIN(pathlen, consumed);
> 	*pp_targetpath = talloc_strdup(ctx, &dfs_path[consumed]);
> 	if (!*pp_targetpath) {
>+		TALLOC_FREE(dfs_refs);
> 		return false;
> 	}
> 	dfs_path[consumed] = '\0';
>@@ -904,21 +966,6 @@ bool cli_resolve_path(TALLOC_CTX *ctx,
> 	 * (in \server\share\path format).
>  	 */
> 
>-	/* Open the connection to the target server & share */
>-	if ((*targetcli = cli_cm_open(ctx, rootcli,
>-					server,
>-					share,
>-					dfs_auth_info,
>-					false,
>-					(rootcli->trans_enc_state != NULL),
>-					rootcli->protocol,
>-					0,
>-					0x20)) == NULL) {
>-		d_printf("Unable to follow dfs referral [\\%s\\%s]\n",
>-			server, share );
>-		return false;
>-	}
>-
> 	if (extrapath && strlen(extrapath) > 0) {
> 		/* EMC Celerra NAS version 5.6.50 (at least) doesn't appear to */
> 		/* put the trailing \ on the path, so to be save we put one in if needed */
>@@ -934,6 +981,7 @@ bool cli_resolve_path(TALLOC_CTX *ctx,
> 						  *pp_targetpath);
> 		}
> 		if (!*pp_targetpath) {
>+			TALLOC_FREE(dfs_refs);
> 			return false;
> 		}
> 	}
>@@ -947,18 +995,21 @@ bool cli_resolve_path(TALLOC_CTX *ctx,
> 		d_printf("cli_resolve_path: "
> 			"dfs_path (%s) not in correct format.\n",
> 			dfs_path );
>+		TALLOC_FREE(dfs_refs);
> 		return false;
> 	}
> 
> 	ppath++; /* Now pointing at start of server name. */
> 
> 	if ((ppath = strchr_m( dfs_path, '\\' )) == NULL) {
>+		TALLOC_FREE(dfs_refs);
> 		return false;
> 	}
> 
> 	ppath++; /* Now pointing at start of share name. */
> 
> 	if ((ppath = strchr_m( ppath+1, '\\' )) == NULL) {
>+		TALLOC_FREE(dfs_refs);
> 		return false;
> 	}
> 
>@@ -966,6 +1017,7 @@ bool cli_resolve_path(TALLOC_CTX *ctx,
> 
> 	newmount = talloc_asprintf(ctx, "%s\\%s", mountpt, ppath );
> 	if (!newmount) {
>+		TALLOC_FREE(dfs_refs);
> 		return false;
> 	}
> 
>@@ -989,6 +1041,7 @@ bool cli_resolve_path(TALLOC_CTX *ctx,
>  			 */
> 			*targetcli = newcli;
> 			*pp_targetpath = newpath;
>+			TALLOC_FREE(dfs_refs);
> 			return true;
> 		}
> 	}
>@@ -999,11 +1052,13 @@ bool cli_resolve_path(TALLOC_CTX *ctx,
> 	if ((*targetcli)->dfsroot) {
> 		dfs_path = talloc_strdup(ctx, *pp_targetpath);
> 		if (!dfs_path) {
>+			TALLOC_FREE(dfs_refs);
> 			return false;
> 		}
> 		*pp_targetpath = cli_dfs_make_full_path(ctx, *targetcli, dfs_path);
> 	}
> 
>+	TALLOC_FREE(dfs_refs);
> 	return true;
> }
> 
>-- 
>2.1.2
>

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