Changeset 745 for trunk/server/source3/smbd/smb2_read.c

Timestamp:

Nov 27, 2012, 4:43:17 PM (13 years ago)

Author:

Silvan Scherrer

Message:

Samba Server: updated trunk to 3.6.0

Location:

trunk/server

Files:

• . (modified) (1 prop)
• source3/smbd/smb2_read.c (modified) (11 diffs)

trunk/server/source3/smbd/smb2_read.c

@@ -20 +20 @@
 
 #include "includes.h"
+#include "system/filesys.h"
+#include "smbd/smbd.h"
 #include "smbd/globals.h"
 #include "../libcli/smb/smb_common.h"
+#include "libcli/security/security.h"
+#include "../lib/util/tevent_ntstatus.h"
+#include "rpc_server/srv_pipe_hnd.h"
 
 static struct tevent_req *smbd_smb2_read_send(TALLOC_CTX *mem_ctx,
@@ -76 +81 @@
 
         /* check the max read size */
-        if (in_length > 0x00010000) {
+        if (in_length > lp_smb2_max_read()) {
                 DEBUG(0,("here:%s: 0x%08X: 0x%08X\n",
-                        __location__, in_length, 0x00010000));
+                        __location__, in_length, lp_smb2_max_read()));
                 return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
         }
@@ -84 +89 @@
         if (req->compat_chain_fsp) {
                 /* skip check */
-        } else if (in_file_id_persistent != 0) {
+        } else if (in_file_id_persistent != in_file_id_volatile) {
                 return smbd_smb2_request_error(req, NT_STATUS_FILE_CLOSED);
         }
@@ -171 +176 @@
 struct smbd_smb2_read_state {
         struct smbd_smb2_request *smb2req;
+        files_struct *fsp;
+        uint64_t in_file_id_volatile;
+        uint32_t in_length;
+        uint64_t in_offset;
+        uint32_t in_minimum;
         DATA_BLOB out_data;
         uint32_t out_remaining;
 };
 
+/* struct smbd_smb2_read_state destructor. Send the SMB2_READ data. */
+static int smb2_sendfile_send_data(struct smbd_smb2_read_state *state)
+{
+        struct lock_struct lock;
+        uint32_t in_length = state->in_length;
+        uint64_t in_offset = state->in_offset;
+        files_struct *fsp = state->fsp;
+        ssize_t nread;
+
+        nread = SMB_VFS_SENDFILE(fsp->conn->sconn->sock,
+                                        fsp,
+                                        NULL,
+                                        in_offset,
+                                        in_length);
+        DEBUG(10,("smb2_sendfile_send_data: SMB_VFS_SENDFILE returned %d on file %s\n",
+                (int)nread,
+                fsp_str_dbg(fsp) ));
+
+        if (nread == -1) {
+                if (errno == ENOSYS || errno == EINTR) {
+                        /*
+                         * Special hack for broken systems with no working
+                         * sendfile. Fake this up by doing read/write calls.
+                        */
+                        set_use_sendfile(SNUM(fsp->conn), false);
+                        nread = fake_sendfile(fsp, in_offset, in_length);
+                        if (nread == -1) {
+                                DEBUG(0,("smb2_sendfile_send_data: "
+                                        "fake_sendfile failed for "
+                                        "file %s (%s).\n",
+                                        fsp_str_dbg(fsp),
+                                        strerror(errno)));
+                                exit_server_cleanly("smb2_sendfile_send_data: "
+                                        "fake_sendfile failed");
+                        }
+                        goto out;
+                }
+
+                DEBUG(0,("smb2_sendfile_send_data: sendfile failed for file "
+                        "%s (%s). Terminating\n",
+                        fsp_str_dbg(fsp),
+                        strerror(errno)));
+                exit_server_cleanly("smb2_sendfile_send_data: sendfile failed");
+        } else if (nread == 0) {
+                /*
+                 * Some sendfile implementations return 0 to indicate
+                 * that there was a short read, but nothing was
+                 * actually written to the socket.  In this case,
+                 * fallback to the normal read path so the header gets
+                 * the correct byte count.
+                 */
+                DEBUG(3, ("send_file_readX: sendfile sent zero bytes "
+                        "falling back to the normal read: %s\n",
+                        fsp_str_dbg(fsp)));
+
+                nread = fake_sendfile(fsp, in_offset, in_length);
+                if (nread == -1) {
+                        DEBUG(0,("smb2_sendfile_send_data: "
+                                "fake_sendfile failed for file "
+                                "%s (%s). Terminating\n",
+                                fsp_str_dbg(fsp),
+                                strerror(errno)));
+                        exit_server_cleanly("smb2_sendfile_send_data: "
+                                "fake_sendfile failed");
+                }
+        }
+
+  out:
+
+        if (nread < in_length) {
+                sendfile_short_send(fsp, nread, 0, in_length);
+        }
+
+        init_strict_lock_struct(fsp,
+                                state->in_file_id_volatile,
+                                in_offset,
+                                in_length,
+                                READ_LOCK,
+                                &lock);
+
+        SMB_VFS_STRICT_UNLOCK(fsp->conn, fsp, &lock);
+        return 0;
+}
+
+static NTSTATUS schedule_smb2_sendfile_read(struct smbd_smb2_request *smb2req,
+                                        struct smbd_smb2_read_state *state)
+{
+        struct smbd_smb2_read_state *state_copy = NULL;
+        files_struct *fsp = state->fsp;
+
+        /*
+         * We cannot use sendfile if...
+         * We were not configured to do so OR
+         * Signing is active OR
+         * This is a compound SMB2 operation OR
+         * fsp is a STREAM file OR
+         * We're using a write cache OR
+         * It's not a regular file OR
+         * Requested offset is greater than file size OR
+         * there's not enough data in the file.
+         * Phew :-). Luckily this means most
+         * reads on most normal files. JRA.
+        */
+
+        if (!_lp_use_sendfile(SNUM(fsp->conn)) ||
+                        smb2req->do_signing ||
+                        smb2req->in.vector_count != 4 ||
+                        (fsp->base_fsp != NULL) ||
+                        (fsp->wcp != NULL) ||
+                        (!S_ISREG(fsp->fsp_name->st.st_ex_mode)) ||
+                        (state->in_offset >= fsp->fsp_name->st.st_ex_size) ||
+                        (fsp->fsp_name->st.st_ex_size < state->in_offset +
+                                state->in_length)) {
+                return NT_STATUS_RETRY;
+        }
+
+        /* We've already checked there's this amount of data
+           to read. */
+        state->out_data.length = state->in_length;
+        state->out_remaining = 0;
+
+        /* Make a copy of state attached to the smb2req. Attach
+           the destructor here as this will trigger the sendfile
+           call when the request is destroyed. */
+        state_copy = TALLOC_P(smb2req, struct smbd_smb2_read_state);
+        if (!state_copy) {
+                return NT_STATUS_NO_MEMORY;
+        }
+        *state_copy = *state;
+        talloc_set_destructor(state_copy, smb2_sendfile_send_data);
+        return NT_STATUS_OK;
+}
+
 static void smbd_smb2_read_pipe_done(struct tevent_req *subreq);
+
+/*******************************************************************
+ Common read complete processing function for both synchronous and
+ asynchronous reads.
+*******************************************************************/
+
+NTSTATUS smb2_read_complete(struct tevent_req *req, ssize_t nread, int err)
+{
+        struct smbd_smb2_read_state *state = tevent_req_data(req,
+                                        struct smbd_smb2_read_state);
+        files_struct *fsp = state->fsp;
+
+        if (nread < 0) {
+                NTSTATUS status = map_nt_error_from_unix(err);
+
+                DEBUG( 3,( "smb2_read_complete: file %s nread = %d. "
+                        "Error = %s (NTSTATUS %s)\n",
+                        fsp_str_dbg(fsp),
+                        (int)nread,
+                        strerror(err),
+                        nt_errstr(status)));
+
+                return status;
+        }
+        if (nread == 0 && state->in_length != 0) {
+                DEBUG(5,("smb2_read_complete: read_file[%s] end of file\n",
+                        fsp_str_dbg(fsp)));
+                return NT_STATUS_END_OF_FILE;
+        }
+
+        if (nread < state->in_minimum) {
+                DEBUG(5,("smb2_read_complete: read_file[%s] read less %d than "
+                        "minimum requested %u. Returning end of file\n",
+                        fsp_str_dbg(fsp),
+                        (int)nread,
+                        (unsigned int)state->in_minimum));
+                return NT_STATUS_END_OF_FILE;
+        }
+
+        DEBUG(3,("smbd_smb2_read: fnum=[%d/%s] length=%lu offset=%lu read=%lu\n",
+                fsp->fnum,
+                fsp_str_dbg(fsp),
+                (unsigned long)state->in_length,
+                (unsigned long)state->in_offset,
+                (unsigned long)nread));
+
+        state->out_data.length = nread;
+        state->out_remaining = 0;
+
+        return NT_STATUS_OK;
+}
 
 static struct tevent_req *smbd_smb2_read_send(TALLOC_CTX *mem_ctx,
@@ -187 +381 @@
                                               uint32_t in_remaining)
 {
-        struct tevent_req *req;
-        struct smbd_smb2_read_state *state;
-        struct smb_request *smbreq;
+        NTSTATUS status;
+        struct tevent_req *req = NULL;
+        struct smbd_smb2_read_state *state = NULL;
+        struct smb_request *smbreq = NULL;
         connection_struct *conn = smb2req->tcon->compat_conn;
-        files_struct *fsp;
+        files_struct *fsp = NULL;
         ssize_t nread = -1;
         struct lock_struct lock;
+        int saved_errno;
 
         req = tevent_req_create(mem_ctx, &state,
@@ -201 +397 @@
         }
         state->smb2req = smb2req;
+        state->in_length = in_length;
+        state->in_offset = in_offset;
+        state->in_minimum = in_minimum;
         state->out_data = data_blob_null;
         state->out_remaining = 0;
@@ -225 +424 @@
                 return tevent_req_post(req, ev);
         }
-
-        state->out_data = data_blob_talloc(state, NULL, in_length);
-        if (in_length > 0 && tevent_req_nomem(state->out_data.data, req)) {
-                return tevent_req_post(req, ev);
-        }
+        if (fsp->is_directory) {
+                tevent_req_nterror(req, NT_STATUS_INVALID_DEVICE_REQUEST);
+                return tevent_req_post(req, ev);
+        }
+
+        state->fsp = fsp;
+        state->in_file_id_volatile = in_file_id_volatile;
 
         if (IS_IPC(smbreq->conn)) {
-                struct tevent_req *subreq;
+                struct tevent_req *subreq = NULL;
+
+                state->out_data = data_blob_talloc(state, NULL, in_length);
+                if (in_length > 0 && tevent_req_nomem(state->out_data.data, req)) {
+                        return tevent_req_post(req, ev);
+                }
 
                 if (!fsp_is_np(fsp)) {
@@ -257 +463 @@
         }
 
+        status = schedule_smb2_aio_read(fsp->conn,
+                                smbreq,
+                                fsp,
+                                state,
+                                &state->out_data,
+                                (SMB_OFF_T)in_offset,
+                                (size_t)in_length);
+
+        if (NT_STATUS_IS_OK(status)) {
+                /*
+                 * Doing an async read. Don't
+                 * send a "gone async" message
+                 * as we expect this to be less
+                 * than the client timeout period.
+                 * JRA. FIXME for offline files..
+                 * FIXME. Add cancel code..
+                 */
+                smb2req->async = true;
+                return req;
+        }
+
+        if (!NT_STATUS_EQUAL(status, NT_STATUS_RETRY)) {
+                /* Real error in setting up aio. Fail. */
+                tevent_req_nterror(req, NT_STATUS_FILE_CLOSED);
+                return tevent_req_post(req, ev);
+        }
+
+        /* Fallback to synchronous. */
+
         init_strict_lock_struct(fsp,
-                                in_smbpid,
+                                in_file_id_volatile,
                                 in_offset,
                                 in_length,
@@ -269 +504 @@
         }
 
+        /* Try sendfile in preference. */
+        status = schedule_smb2_sendfile_read(smb2req, state);
+        if (NT_STATUS_IS_OK(status)) {
+                tevent_req_done(req);
+                return tevent_req_post(req, ev);
+        } else {
+                if (!NT_STATUS_EQUAL(status, NT_STATUS_RETRY)) {
+                        SMB_VFS_STRICT_UNLOCK(conn, fsp, &lock);
+                        tevent_req_nterror(req, status);
+                        return tevent_req_post(req, ev);
+                }
+        }
+
+        /* Ok, read into memory. Allocate the out buffer. */
+        state->out_data = data_blob_talloc(state, NULL, in_length);
+        if (in_length > 0 && tevent_req_nomem(state->out_data.data, req)) {
+                SMB_VFS_STRICT_UNLOCK(conn, fsp, &lock);
+                return tevent_req_post(req, ev);
+        }
+
         nread = read_file(fsp,
                           (char *)state->out_data.data,
@@ -274 +529 @@
                           in_length);
 
+        saved_errno = errno;
+
         SMB_VFS_STRICT_UNLOCK(conn, fsp, &lock);
 
-        if (nread < 0) {
-                DEBUG(5,("smbd_smb2_read: read_file[%s] nread[%lld]\n",
-                         fsp_str_dbg(fsp), (long long)nread));
-                tevent_req_nterror(req, NT_STATUS_ACCESS_DENIED);
-                return tevent_req_post(req, ev);
-        }
-        if (nread == 0 && in_length != 0) {
-                DEBUG(5,("smbd_smb2_read: read_file[%s] end of file\n",
-                         fsp_str_dbg(fsp)));
-                tevent_req_nterror(req, NT_STATUS_END_OF_FILE);
-                return tevent_req_post(req, ev);
-        }
-
-        state->out_data.length = nread;
-        state->out_remaining = 0;
-        tevent_req_done(req);
+        DEBUG(10,("smbd_smb2_read: file %s handle [0x%016llX] offset=%llu "
+                "len=%llu returned %lld\n",
+                fsp_str_dbg(fsp),
+                (unsigned long long)in_file_id_volatile,
+                (unsigned long long)in_offset,
+                (unsigned long long)in_length,
+                (long long)nread));
+
+        status = smb2_read_complete(req, nread, saved_errno);
+        if (!NT_STATUS_IS_OK(status)) {
+                tevent_req_nterror(req, status);
+        } else {
+                /* Success. */
+                tevent_req_done(req);
+        }
         return tevent_req_post(req, ev);
 }
@@ -320 +576 @@
         state->out_remaining = 0;
 
+        /*
+         * TODO: add STATUS_BUFFER_OVERFLOW handling, once we also
+         * handle it in SMB1 pipe_read_andx_done().
+         */
+
         tevent_req_done(req);
 }