smb_traffic_analyzer.c: optimize marshalling function and document

Collect all data that is needed, and use only one talloc_asprintf
operation to create the string of common data. This simplifies
the code a bit and is most probably faster than the old method.

Also, #define SMBTA_COMMON_DATA_COUNT as a complete string,
speeding things up because we know the value at compile time.

diff --git a/source3/modules/vfs_smb_traffic_analyzer.c b/source3/modules/vfs_smb_traffic_analyzer.c
index 814710f01ce2fd3ab3a7ebc1718d812343627516..99c32333a264bbaa96d2603c1879b0ac548d1744 100644 (file)
--- a/source3/modules/vfs_smb_traffic_analyzer.c
+++ b/source3/modules/vfs_smb_traffic_analyzer.c
@@ -269,7 +269,21 @@ static char *smb_traffic_analyzer_anonymize( TALLOC_CTX *ctx,
 }
 
 
-/* The marshaller for the protocol version 2. */
+/**
+ * The marshalling function for protocol v2.
+ * TALLOC_CTX *ctx             Talloc context to work on
+ * struct tm *tm               tm struct for the timestamp
+ * int seconds                 milliseconds of the timestamp
+ * vfs_handle_struct *handle   vfs_handle_struct
+ * char *username              Name of the user
+ * int vfs_operation           VFS operation identifier
+ * int count                   Number of the common data blocks
+ * [...] variable args         data blocks taken from the individual
+ *                             VFS data structures
+ *
+ * Returns the complete data block to send. The caller has to
+ * take care for freeing the allocated buffer.
+ */
 static char *smb_traffic_analyzer_create_string( TALLOC_CTX *ctx,
        struct tm *tm, int seconds, vfs_handle_struct *handle, \
        char *username, int vfs_operation, int count, ... )
@@ -279,11 +293,12 @@ static char *smb_traffic_analyzer_create_string( TALLOC_CTX *ctx,
        char *arg = NULL;
        int len;
        char *header = NULL;
-       char *buf = NULL;
+       char *common_data_count_str = NULL;
        char *timestr = NULL;
-       char *opstr = NULL;
        char *sidstr = NULL;
        char *usersid = NULL;
+       char *buf = NULL;
+       char *vfs_operation_str = NULL;
        /*
         * first create the data that is transfered with any VFS op
         * These are, in the following order:
@@ -296,42 +311,30 @@ static char *smb_traffic_analyzer_create_string( TALLOC_CTX *ctx,
         * 6.timestamp
         */
 
-       /* number of common data blocks to come */
-       opstr = talloc_asprintf( ctx, "%i", SMBTA_COMMON_DATA_COUNT);
-       len = strlen(opstr);
-       buf = talloc_asprintf( ctx, "%04u%s", len, opstr);
-       talloc_free(opstr);
+       /*
+        * number of common data blocks to come,
+        * this is a #define in vfs_smb_traffic_anaylzer.h,
+        * it's length is known at compile time
+        */
+       common_data_count_str = talloc_strdup( ctx, SMBTA_COMMON_DATA_COUNT);
        /* vfs operation identifier */
-       opstr = talloc_asprintf( ctx, "%i", vfs_operation);
-       len = strlen(opstr);
-       buf = talloc_asprintf_append( buf, "%04u%s", len, opstr);
-       talloc_free(opstr);
+       vfs_operation_str = talloc_asprintf( common_data_count_str, "%i",
+                                                       vfs_operation);
        /*
         * Handle anonymization. In protocol v2, we have to anonymize
         * both the SID and the username. The name is already
         * anonymized if needed, by the calling function.
         */
-       usersid = dom_sid_string( ctx,
+       usersid = dom_sid_string( common_data_count_str,
                &handle->conn->server_info->ptok->user_sids[0]);
-       sidstr = smb_traffic_analyzer_anonymize(ctx, usersid, handle);
-       talloc_free(usersid);
-       /* username */
-       len = strlen( username );
-       buf = talloc_asprintf_append(buf, "%04u%s", len, username);
-       /* user SID */
-       len = strlen( sidstr );
-       buf = talloc_asprintf_append(buf, "%04u%s", len, sidstr);
-       talloc_free(sidstr);
-       /* affected share */
-       len = strlen( handle->conn->connectpath );
-       buf = talloc_asprintf_append( buf, "%04u%s", len, \
-               handle->conn->connectpath );
-       /* user's domain */
-       len = strlen( pdb_get_domain(handle->conn->server_info->sam_account) );
-       buf = talloc_asprintf_append( buf, "%04u%s", len, \
-               pdb_get_domain(handle->conn->server_info->sam_account) );
+
+       sidstr = smb_traffic_analyzer_anonymize(
+               common_data_count_str,
+               usersid,
+               handle);
+       
        /* time stamp */
-       timestr = talloc_asprintf( ctx, \
+       timestr = talloc_asprintf( common_data_count_str, \
                "%04d-%02d-%02d %02d:%02d:%02d.%03d", \
                tm->tm_year+1900, \
                tm->tm_mon+1, \
@@ -341,8 +344,25 @@ static char *smb_traffic_analyzer_create_string( TALLOC_CTX *ctx,
                tm->tm_sec, \
                (int)seconds);
        len = strlen( timestr );
-       buf = talloc_asprintf_append( buf, "%04u%s", len, timestr);
-       talloc_free(timestr);
+       /* create the string of common data */
+       buf = talloc_asprintf(ctx,
+               "%s%04u%s%04u%s%04u%s%04u%s%04u%s%04u%s",
+               common_data_count_str,
+               strlen(vfs_operation_str),
+               vfs_operation_str,
+               strlen(username),
+               username,
+               strlen(sidstr),
+               sidstr,
+               strlen(handle->conn->connectpath),
+               handle->conn->connectpath,
+               strlen(pdb_get_domain(handle->conn->server_info->sam_account)),
+               pdb_get_domain(handle->conn->server_info->sam_account),
+               strlen(timestr),
+               timestr);
+
+       talloc_free(common_data_count_str);
+
        /* data blocks depending on the VFS function */ 
        va_start( ap, count );
        while ( count-- ) {

diff --git a/source3/modules/vfs_smb_traffic_analyzer.h b/source3/modules/vfs_smb_traffic_analyzer.h
index f3d902754e650144ee02eb5787ed74460fd2c7c2..1e8375d17b5109c3674d7ce3a91ee068a5a95d42 100644 (file)
--- a/source3/modules/vfs_smb_traffic_analyzer.h
+++ b/source3/modules/vfs_smb_traffic_analyzer.h
@@ -85,7 +85,7 @@
  * so that if the receiver is using an older version of the protocol
  * it knows which blocks it can ignore.
  */
-#define SMBTA_COMMON_DATA_COUNT 6
+#define SMBTA_COMMON_DATA_COUNT "00016"
 
 /*
  * VFS Functions identifier table. In protocol version 2, every vfs