s3-utils/net_rpc_printer.c: print more info on write error

[Samba/gebeck_regimport.git] / source3 / libsmb / smb2cli_base.c

/*
   Unix SMB/CIFS implementation.
   smb2 lib
   Copyright (C) Volker Lendecke 2011
   Copyright (C) Stefan Metzmacher 2011

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"
#include "client.h"
#include "read_smb.h"
#include "smb2cli_base.h"
#include "lib/async_req/async_sock.h"
#include "lib/util/tevent_ntstatus.h"

struct smb2cli_req_state {
        struct tevent_context *ev;
        struct cli_state *cli;

        const uint8_t *fixed;
        uint16_t fixed_len;
        const uint8_t *dyn;
        uint16_t dyn_len;

        uint8_t nbt[4];
        uint8_t hdr[64];
        uint8_t pad[7]; /* padding space for compounding */

        /* always an array of 3 talloc elements */
        struct iovec *recv_iov;
};

static void smb2cli_req_unset_pending(struct tevent_req *req)
{
        struct smb2cli_req_state *state =
                tevent_req_data(req,
                struct smb2cli_req_state);
        struct cli_state *cli = state->cli;
        int num_pending = talloc_array_length(cli->conn.pending);
        int i;

        talloc_set_destructor(req, NULL);

        if (num_pending == 1) {
                /*
                 * The pending read_smb tevent_req is a child of
                 * cli->conn.pending. So if nothing is pending anymore,
                 * we need to delete the socket read fde.
                 */
                TALLOC_FREE(cli->conn.pending);
                return;
        }

        for (i=0; i<num_pending; i++) {
                if (req == cli->conn.pending[i]) {
                        break;
                }
        }
        if (i == num_pending) {
                /*
                 * Something's seriously broken. Just returning here is the
                 * right thing nevertheless, the point of this routine is to
                 * remove ourselves from cli->conn.pending.
                 */
                return;
        }

        /*
         * Remove ourselves from the cli->pending array
         */
        for (; i < (num_pending - 1); i++) {
                cli->conn.pending[i] = cli->conn.pending[i+1];
        }

        /*
         * No NULL check here, we're shrinking by sizeof(void *), and
         * talloc_realloc just adjusts the size for this.
         */
        cli->conn.pending = talloc_realloc(NULL, cli->conn.pending,
                                           struct tevent_req *,
                                           num_pending - 1);
        return;
}

static int smb2cli_req_destructor(struct tevent_req *req)
{
        smb2cli_req_unset_pending(req);
        return 0;
}

static void smb2cli_inbuf_received(struct tevent_req *subreq);

static bool smb2cli_req_set_pending(struct tevent_req *req)
{
        struct smb2cli_req_state *state =
                tevent_req_data(req,
                struct smb2cli_req_state);
        struct cli_state *cli;
        struct tevent_req **pending;
        int num_pending;
        struct tevent_req *subreq;

        cli = state->cli;
        num_pending = talloc_array_length(cli->conn.pending);

        pending = talloc_realloc(cli, cli->conn.pending, struct tevent_req *,
                                 num_pending+1);
        if (pending == NULL) {
                return false;
        }
        pending[num_pending] = req;
        cli->conn.pending = pending;
        talloc_set_destructor(req, smb2cli_req_destructor);

        if (num_pending > 0) {
                return true;
        }

        /*
         * We're the first ones, add the read_smb request that waits for the
         * answer from the server
         */
        subreq = read_smb_send(cli->conn.pending, state->ev, cli->conn.fd);
        if (subreq == NULL) {
                smb2cli_req_unset_pending(req);
                return false;
        }
        tevent_req_set_callback(subreq, smb2cli_inbuf_received, cli);
        return true;
}

static void smb2cli_notify_pending(struct cli_state *cli, NTSTATUS status)
{
        if (cli->conn.fd != -1) {
                close(cli->conn.fd);
        }
        cli->conn.fd = -1;

        /*
         * Cancel all pending requests. We don't do a for-loop walking
         * cli->conn.pending because that array changes in
         * cli_smb_req_destructor().
         */
        while (talloc_array_length(cli->conn.pending) > 0) {
                struct tevent_req *req;
                struct smb2cli_req_state *state;

                req = cli->conn.pending[0];
                state = tevent_req_data(req, struct smb2cli_req_state);

                smb2cli_req_unset_pending(req);

                /*
                 * we need to defer the callback, because we may notify more
                 * then one caller.
                 */
                tevent_req_defer_callback(req, state->ev);
                tevent_req_nterror(req, status);
        }
}

struct tevent_req *smb2cli_req_create(TALLOC_CTX *mem_ctx,
                                      struct tevent_context *ev,
                                      struct cli_state *cli,
                                      uint16_t cmd,
                                      uint32_t flags,
                                      const uint8_t *fixed,
                                      uint16_t fixed_len,
                                      const uint8_t *dyn,
                                      uint16_t dyn_len)
{
        struct tevent_req *req;
        struct smb2cli_req_state *state;

        req = tevent_req_create(mem_ctx, &state,
                                struct smb2cli_req_state);
        if (req == NULL) {
                return NULL;
        }
        state->ev = ev;
        state->cli = cli;

        state->recv_iov = talloc_zero_array(state, struct iovec, 3);
        if (state->recv_iov == NULL) {
                TALLOC_FREE(req);
                return NULL;
        }

        state->fixed = fixed;
        state->fixed_len = fixed_len;
        state->dyn = dyn;
        state->dyn_len = dyn_len;

        SIVAL(state->hdr, SMB2_HDR_PROTOCOL_ID, SMB2_MAGIC);
        SSVAL(state->hdr, SMB2_HDR_LENGTH,      SMB2_HDR_BODY);
        SSVAL(state->hdr, SMB2_HDR_EPOCH,       1);
        SIVAL(state->hdr, SMB2_HDR_STATUS,      NT_STATUS_V(NT_STATUS_OK));
        SSVAL(state->hdr, SMB2_HDR_OPCODE,      cmd);
        SSVAL(state->hdr, SMB2_HDR_CREDIT,      31);
        SIVAL(state->hdr, SMB2_HDR_FLAGS,       flags);
        SIVAL(state->hdr, SMB2_HDR_PID,         cli->smb2.pid);
        SIVAL(state->hdr, SMB2_HDR_TID,         cli->smb2.tid);
        SBVAL(state->hdr, SMB2_HDR_SESSION_ID,  cli->smb2.uid);

        return req;
}

static void smb2cli_writev_done(struct tevent_req *subreq);

NTSTATUS smb2cli_req_compound_submit(struct tevent_req **reqs,
                                     int num_reqs)
{
        struct smb2cli_req_state *state;
        struct tevent_req *subreq;
        struct iovec *iov;
        int i, num_iov, nbt_len;

        /*
         * 1 for the nbt length
         * per request: HDR, fixed, dyn, padding
         * -1 because the last one does not need padding
         */

        iov = talloc_array(reqs[0], struct iovec, 1 + 4*num_reqs - 1);
        if (iov == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        num_iov = 1;
        nbt_len = 0;

        for (i=0; i<num_reqs; i++) {
                size_t reqlen;
                bool ret;

                state = tevent_req_data(reqs[i], struct smb2cli_req_state);

                SBVAL(state->hdr, SMB2_HDR_MESSAGE_ID, state->cli->smb2.mid++);

                iov[num_iov].iov_base = state->hdr;
                iov[num_iov].iov_len  = sizeof(state->hdr);
                num_iov += 1;

                iov[num_iov].iov_base = discard_const(state->fixed);
                iov[num_iov].iov_len  = state->fixed_len;
                num_iov += 1;

                if (state->dyn != NULL) {
                        iov[num_iov].iov_base = discard_const(state->dyn);
                        iov[num_iov].iov_len  = state->dyn_len;
                        num_iov += 1;
                }

                reqlen = sizeof(state->hdr) + state->fixed_len +
                        state->dyn_len;

                if (i < num_reqs-1) {
                        if ((reqlen % 8) > 0) {
                                uint8_t pad = 8 - (reqlen % 8);
                                iov[num_iov].iov_base = state->pad;
                                iov[num_iov].iov_len = pad;
                                num_iov += 1;
                                reqlen += pad;
                        }
                        SIVAL(state->hdr, SMB2_HDR_NEXT_COMMAND, reqlen);
                }
                nbt_len += reqlen;

                ret = smb2cli_req_set_pending(reqs[i]);
                if (!ret) {
                        return NT_STATUS_NO_MEMORY;
                }
        }

        /*
         * TODO: Do signing here
         */

        state = tevent_req_data(reqs[0], struct smb2cli_req_state);
        _smb_setlen_large(state->nbt, nbt_len);
        iov[0].iov_base = state->nbt;
        iov[0].iov_len  = sizeof(state->nbt);

        subreq = writev_send(state, state->ev, state->cli->conn.outgoing,
                             state->cli->conn.fd, false, iov, num_iov);
        if (subreq == NULL) {
                return NT_STATUS_NO_MEMORY;
        }
        tevent_req_set_callback(subreq, smb2cli_writev_done, reqs[0]);
        return NT_STATUS_OK;
}

struct tevent_req *smb2cli_req_send(TALLOC_CTX *mem_ctx,
                                    struct tevent_context *ev,
                                    struct cli_state *cli,
                                    uint16_t cmd,
                                    uint32_t flags,
                                    const uint8_t *fixed,
                                    uint16_t fixed_len,
                                    const uint8_t *dyn,
                                    uint16_t dyn_len)
{
        struct tevent_req *req;
        NTSTATUS status;

        req = smb2cli_req_create(mem_ctx, ev, cli, cmd, flags,
                                 fixed, fixed_len, dyn, dyn_len);
        if (req == NULL) {
                return NULL;
        }
        if (!tevent_req_is_in_progress(req)) {
                return req;
        }
        status = smb2cli_req_compound_submit(&req, 1);
        if (tevent_req_nterror(req, status)) {
                return tevent_req_post(req, ev);
        }
        return req;
}

static void smb2cli_writev_done(struct tevent_req *subreq)
{
        struct tevent_req *req =
                tevent_req_callback_data(subreq,
                struct tevent_req);
        struct smb2cli_req_state *state =
                tevent_req_data(req,
                struct smb2cli_req_state);
        ssize_t nwritten;
        int err;

        nwritten = writev_recv(subreq, &err);
        TALLOC_FREE(subreq);
        if (nwritten == -1) {
                /* here, we need to notify all pending requests */
                smb2cli_notify_pending(state->cli, map_nt_error_from_unix(err));
                return;
        }
}

static NTSTATUS smb2cli_inbuf_parse_compound(uint8_t *buf, TALLOC_CTX *mem_ctx,
                                             struct iovec **piov, int *pnum_iov)
{
        struct iovec *iov;
        int num_iov;
        size_t buflen;
        size_t taken;

        num_iov = 1;

        iov = talloc_array(mem_ctx, struct iovec, num_iov);
        if (iov == NULL) {
                return NT_STATUS_NO_MEMORY;
        }
        iov[0].iov_base = buf;
        iov[0].iov_len = 4;

        buflen = smb_len_large(buf) + 4;
        taken = 4;

        while (taken < buflen) {
                size_t len = buflen - taken;
                uint8_t *hdr = buf + taken;
                struct iovec *cur;
                size_t full_size;
                size_t next_command_ofs;
                uint16_t body_size;
                struct iovec *iov_tmp;

                /*
                 * We need the header plus the body length field
                 */

                if (len < SMB2_HDR_BODY + 2) {
                        DEBUG(10, ("%d bytes left, expected at least %d\n",
                                   (int)len, SMB2_HDR_BODY));
                        goto inval;
                }
                if (IVAL(hdr, 0) != SMB2_MAGIC) {
                        DEBUG(10, ("Got non-SMB2 PDU: %x\n",
                                   IVAL(hdr, 0)));
                        goto inval;
                }
                if (SVAL(hdr, 4) != SMB2_HDR_BODY) {
                        DEBUG(10, ("Got HDR len %d, expected %d\n",
                                   SVAL(hdr, 4), SMB2_HDR_BODY));
                        goto inval;
                }

                full_size = len;
                next_command_ofs = IVAL(hdr, SMB2_HDR_NEXT_COMMAND);
                body_size = SVAL(hdr, SMB2_HDR_BODY);

                if (next_command_ofs != 0) {
                        if (next_command_ofs < (SMB2_HDR_BODY + 2)) {
                                goto inval;
                        }
                        if (next_command_ofs > full_size) {
                                goto inval;
                        }
                        full_size = next_command_ofs;
                }
                if (body_size < 2) {
                        goto inval;
                }
                body_size &= 0xfffe;

                if (body_size > (full_size - SMB2_HDR_BODY)) {
                        goto inval;
                }

                iov_tmp = talloc_realloc(mem_ctx, iov, struct iovec,
                                         num_iov + 3);
                if (iov_tmp == NULL) {
                        TALLOC_FREE(iov);
                        return NT_STATUS_NO_MEMORY;
                }
                iov = iov_tmp;
                cur = &iov[num_iov];
                num_iov += 3;

                cur[0].iov_base = hdr;
                cur[0].iov_len  = SMB2_HDR_BODY;
                cur[1].iov_base = hdr + SMB2_HDR_BODY;
                cur[1].iov_len  = body_size;
                cur[2].iov_base = hdr + SMB2_HDR_BODY + body_size;
                cur[2].iov_len  = full_size - (SMB2_HDR_BODY + body_size);

                taken += full_size;
        }

        *piov = iov;
        *pnum_iov = num_iov;
        return NT_STATUS_OK;

inval:
        TALLOC_FREE(iov);
        return NT_STATUS_INVALID_NETWORK_RESPONSE;
}

static struct tevent_req *cli_smb2_find_pending(struct cli_state *cli,
                                                uint64_t mid)
{
        int num_pending = talloc_array_length(cli->conn.pending);
        int i;

        for (i=0; i<num_pending; i++) {
                struct tevent_req *req = cli->conn.pending[i];
                struct smb2cli_req_state *state =
                        tevent_req_data(req,
                        struct smb2cli_req_state);

                if (mid == BVAL(state->hdr, SMB2_HDR_MESSAGE_ID)) {
                        return req;
                }
        }
        return NULL;
}

static void smb2cli_inbuf_received(struct tevent_req *subreq)
{
        struct cli_state *cli =
                tevent_req_callback_data(subreq,
                struct cli_state);
        TALLOC_CTX *frame = talloc_stackframe();
        struct tevent_req *req;
        struct smb2cli_req_state *state;
        struct iovec *iov;
        int i, num_iov;
        NTSTATUS status;
        uint8_t *inbuf;
        ssize_t received;
        int err;
        size_t num_pending;

        received = read_smb_recv(subreq, frame, &inbuf, &err);
        TALLOC_FREE(subreq);
        if (received == -1) {
                /*
                 * We need to close the connection and notify
                 * all pending requests.
                 */
                smb2cli_notify_pending(cli, map_nt_error_from_unix(err));
                TALLOC_FREE(frame);
                return;
        }

        status = smb2cli_inbuf_parse_compound(inbuf, frame,
                                              &iov, &num_iov);
        if (!NT_STATUS_IS_OK(status)) {
                /*
                 * if we cannot parse the incoming pdu,
                 * the connection becomes unusable.
                 *
                 * We need to close the connection and notify
                 * all pending requests.
                 */
                smb2cli_notify_pending(cli, status);
                TALLOC_FREE(frame);
                return;
        }

        for (i=1; i<num_iov; i+=3) {
                uint8_t *inbuf_ref = NULL;
                struct iovec *cur = &iov[i];
                uint8_t *inhdr = (uint8_t *)cur[0].iov_base;

                req = cli_smb2_find_pending(
                        cli, BVAL(inhdr, SMB2_HDR_MESSAGE_ID));
                if (req == NULL) {
                        /*
                         * TODO: handle oplock breaks and async responses
                         */

                        /*
                         * We need to close the connection and notify
                         * all pending requests.
                         */
                        smb2cli_notify_pending(cli, status);
                        TALLOC_FREE(frame);
                        return;
                }
                smb2cli_req_unset_pending(req);
                state = tevent_req_data(req, struct smb2cli_req_state);

                /*
                 * There might be more than one response
                 * we need to defer the notifications
                 */
                tevent_req_defer_callback(req, state->ev);

                /*
                 * Note: here we use talloc_reference() in a way
                 *       that does not expose it to the caller.
                 */
                inbuf_ref = talloc_reference(state->recv_iov, inbuf);
                if (tevent_req_nomem(inbuf_ref, req)) {
                        continue;
                }

                /* copy the related buffers */
                state->recv_iov[0] = cur[0];
                state->recv_iov[1] = cur[1];
                state->recv_iov[2] = cur[2];

                tevent_req_done(req);
        }

        TALLOC_FREE(frame);

        num_pending = talloc_array_length(cli->conn.pending);
        if (num_pending == 0) {
                /* no more pending requests, so we are done for now */
                return;
        }
        req = cli->conn.pending[0];
        state = tevent_req_data(req, struct smb2cli_req_state);

        /*
         * add the read_smb request that waits for the
         * next answer from the server
         */
        subreq = read_smb_send(cli->conn.pending, state->ev, cli->conn.fd);
        if (subreq == NULL) {
                smb2cli_notify_pending(cli, NT_STATUS_NO_MEMORY);
                return;
        }
        tevent_req_set_callback(subreq, smb2cli_inbuf_received, cli);
}

NTSTATUS smb2cli_req_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
                          struct iovec **piov, int body_size)
{
        struct smb2cli_req_state *state =
                tevent_req_data(req,
                struct smb2cli_req_state);
        NTSTATUS status;

        if (tevent_req_is_nterror(req, &status)) {
                return status;
        }

        status = NT_STATUS(IVAL(state->recv_iov[0].iov_base, SMB2_HDR_STATUS));

        if (body_size != 0) {
                if (body_size != SVAL(state->recv_iov[1].iov_base, 0)) {
                        return NT_STATUS_INVALID_NETWORK_RESPONSE;
                }
        }
        if (piov != NULL) {
                *piov = talloc_move(mem_ctx, &state->recv_iov);
        }

        return status;
}