Memory leak in using smb2_read()?

[Sun_Peixing at emc.com]

Hi All:

 

I am suing Samba4, patch6.   I am writing a test case that read a lot a
large file using smb2_read.

 

I understand that the data returned from function smb2_read() is stored
in struct smb2_read.out.data, which is a DATA_BLOB type that is
dynamically allocated inside function smb2_read().

 

Do we need free the memory used by smb2_read.out.data?  I checked the
examples of Samba4, I didn't see any of them free the memory used by
smb2_read.out.data.   Will this cause memory leaks?

 

To put it simple, memory is dynamically allocated inside function
smb2_read(), why there is no free in the samba 4 code where smb2_read is
called?

 

Following is my code snippet, the struct of smb2_read and function
smb2_read comes with Smaba4.

 

Thanks advance for any help or information

 

Peixing

 

================================================= 

 

NTSTATUS  test_smb2_read(){

 

     struct smb2_read r;

     int total_data_size_read =0;

 

 

     while(total_data_size_written < file_size){

        

         ZERO_STRUCT(r);

         r.in.file.handle = handle;

         r.in.length      = 8192;

         r.in.offset      = total_data_size_read;

 

         status = smb2_read(tree, mem_ctx, &r);

 

 

         if(!NT_STATUS_IS_OK(status)) {

                 printf("ERROR: smb2_read failed - %s\n",
nt_errstr(status));

                 return status;

       }

 

      total_data_size_read += r.out.data.length;

      

     }

}

 

======================================

 

libcli/raw/interfaces.h

 

  struct smb2_read {

                enum smb_read_level level;

                struct {

                        union smb_handle file;

 

                        /* static body buffer 48 (0x30) bytes */

                        /* uint16_t buffer_code;  0x31 = 0x30 + 1 */

                        uint8_t _pad;

                        uint8_t reserved;

                        uint32_t length;

                        uint64_t offset;

                        /* struct smb2_handle handle; */

                        uint32_t min_count;

                        uint32_t channel;

                        uint32_t remaining;

                        /* the docs give no indication of what

                           these channel variables are for */

                        uint16_t channel_offset;

                        uint16_t channel_length;

                } in;

                struct {

                        /* static body buffer 16 (0x10) bytes */

                        /* uint16_t buffer_code;  0x11 = 0x10 + 1 */

                        /* uint8_t data_ofs; */

                        /* uint8_t reserved; */

                        /* uint32_t data_size; */

                        uint32_t remaining;

                        uint32_t reserved;

 

                        /* dynamic body */

                        DATA_BLOB data;

                } out;

        } smb2;

 

 

libcli/smb2/read.c

 

/*

  send a read request

*/

struct smb2_request *smb2_read_send(struct smb2_tree *tree, struct
smb2_read *io) {

        struct smb2_request *req;

 

        req = smb2_request_init_tree(tree, SMB2_OP_READ, 0x30, true, 0);

        if (req == NULL) return NULL;

 

        SCVAL(req->out.body, 0x02, 0); /* pad */

        SCVAL(req->out.body, 0x03, 0); /* reserved */

        SIVAL(req->out.body, 0x04, io->in.length);

        SBVAL(req->out.body, 0x08, io->in.offset);

        smb2_push_handle(req->out.body+0x10, &io->in.file.handle);

        SIVAL(req->out.body, 0x20, io->in.min_count);

        SIVAL(req->out.body, 0x24, io->in.channel);

        SIVAL(req->out.body, 0x28, io->in.remaining);

        SSVAL(req->out.body, 0x2C, io->in.channel_offset);

        SSVAL(req->out.body, 0x2E, io->in.channel_length);

 

        smb2_transport_send(req);

 

        return req;

}

 

 

/*

  recv a read reply

*/

NTSTATUS smb2_read_recv(struct smb2_request *req,

                        TALLOC_CTX *mem_ctx, struct smb2_read *io) {

        NTSTATUS status;

 

        if (!smb2_request_receive(req) ||

            !smb2_request_is_ok(req)) {

                return smb2_request_destroy(req);

        }

 

        SMB2_CHECK_PACKET_RECV(req, 0x10, true);

 

        status = smb2_pull_o16s32_blob(&req->in, mem_ctx,
req->in.body+0x02, &io->out.data);

        if (!NT_STATUS_IS_OK(status)) {

                smb2_request_destroy(req);

                return status;

        }

 

        io->out.remaining = IVAL(req->in.body, 0x08);

        io->out.reserved  = IVAL(req->in.body, 0x0C);

 

        return smb2_request_destroy(req); }

 

/*

  sync read request

*/

NTSTATUS smb2_read(struct smb2_tree *tree, TALLOC_CTX *mem_ctx, struct
smb2_read *io) {

        struct smb2_request *req = smb2_read_send(tree, io);

        return smb2_read_recv(req, mem_ctx, io); }