source: vendor/current/nsswitch/wb_reqtrans.c

/*
   Unix SMB/CIFS implementation.

   Async transfer of winbindd_request and _response structs

   Copyright (C) Volker Lendecke 2008

     ** NOTE! The following LGPL license applies to the wbclient
     ** library. This does NOT imply that all of Samba is released
     ** under the LGPL

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

   This library 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
   Library General Public License for more details.

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

#include "replace.h"
#include "system/filesys.h"
#include "system/network.h"
#include <talloc.h>
#include <tevent.h>
#include "lib/async_req/async_sock.h"
#include "lib/util/tevent_unix.h"
#include "nsswitch/winbind_struct_protocol.h"
#include "nsswitch/libwbclient/wbclient.h"
#include "nsswitch/wb_reqtrans.h"

/* can't use DEBUG here... */
#define DEBUG(a,b)

struct req_read_state {
        struct winbindd_request *wb_req;
        size_t max_extra_data;
        ssize_t ret;
};

static ssize_t wb_req_more(uint8_t *buf, size_t buflen, void *private_data);
static void wb_req_read_done(struct tevent_req *subreq);

struct tevent_req *wb_req_read_send(TALLOC_CTX *mem_ctx,
                                    struct tevent_context *ev,
                                    int fd, size_t max_extra_data)
{
        struct tevent_req *req, *subreq;
        struct req_read_state *state;

        req = tevent_req_create(mem_ctx, &state, struct req_read_state);
        if (req == NULL) {
                return NULL;
        }
        state->max_extra_data = max_extra_data;

        subreq = read_packet_send(state, ev, fd, 4, wb_req_more, state);
        if (tevent_req_nomem(subreq, req)) {
                return tevent_req_post(req, ev);
        }
        tevent_req_set_callback(subreq, wb_req_read_done, req);
        return req;
}

static ssize_t wb_req_more(uint8_t *buf, size_t buflen, void *private_data)
{
        struct req_read_state *state = talloc_get_type_abort(
                private_data, struct req_read_state);
        struct winbindd_request *req = (struct winbindd_request *)buf;

        if (buflen == 4) {
                if (req->length != sizeof(struct winbindd_request)) {
                        DEBUG(0, ("wb_req_read_len: Invalid request size "
                                  "received: %d (expected %d)\n",
                                  (int)req->length,
                                  (int)sizeof(struct winbindd_request)));
                        return -1;
                }
                return sizeof(struct winbindd_request) - 4;
        }

        if (buflen > sizeof(struct winbindd_request)) {
                /* We've been here, we're done */
                return 0;
        }

        if ((state->max_extra_data != 0)
            && (req->extra_len > state->max_extra_data)) {
                DEBUG(3, ("Got request with %d bytes extra data on "
                          "unprivileged socket\n", (int)req->extra_len));
                return -1;
        }

        return req->extra_len;
}

static void wb_req_read_done(struct tevent_req *subreq)
{
        struct tevent_req *req = tevent_req_callback_data(
                subreq, struct tevent_req);
        struct req_read_state *state = tevent_req_data(
                req, struct req_read_state);
        int err;
        uint8_t *buf;

        state->ret = read_packet_recv(subreq, state, &buf, &err);
        TALLOC_FREE(subreq);
        if (state->ret == -1) {
                tevent_req_error(req, err);
                return;
        }

        state->wb_req = (struct winbindd_request *)buf;

        if (state->wb_req->extra_len != 0) {
                state->wb_req->extra_data.data =
                        (char *)buf + sizeof(struct winbindd_request);
        } else {
                state->wb_req->extra_data.data = NULL;
        }
        tevent_req_done(req);
}

ssize_t wb_req_read_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
                         struct winbindd_request **preq, int *err)
{
        struct req_read_state *state = tevent_req_data(
                req, struct req_read_state);

        if (tevent_req_is_unix_error(req, err)) {
                return -1;
        }
        *preq = talloc_move(mem_ctx, &state->wb_req);
        return state->ret;
}

struct req_write_state {
        struct iovec iov[2];
        ssize_t ret;
};

static void wb_req_write_done(struct tevent_req *subreq);

struct tevent_req *wb_req_write_send(TALLOC_CTX *mem_ctx,
                                     struct tevent_context *ev,
                                     struct tevent_queue *queue, int fd,
                                     struct winbindd_request *wb_req)
{
        struct tevent_req *req, *subreq;
        struct req_write_state *state;
        int count = 1;

        req = tevent_req_create(mem_ctx, &state, struct req_write_state);
        if (req == NULL) {
                return NULL;
        }

        state->iov[0].iov_base = (void *)wb_req;
        state->iov[0].iov_len = sizeof(struct winbindd_request);

        if (wb_req->extra_len != 0) {
                state->iov[1].iov_base = (void *)wb_req->extra_data.data;
                state->iov[1].iov_len = wb_req->extra_len;
                count = 2;
        }

        subreq = writev_send(state, ev, queue, fd, true, state->iov, count);
        if (tevent_req_nomem(subreq, req)) {
                return tevent_req_post(req, ev);
        }
        tevent_req_set_callback(subreq, wb_req_write_done, req);
        return req;
}

static void wb_req_write_done(struct tevent_req *subreq)
{
        struct tevent_req *req = tevent_req_callback_data(
                subreq, struct tevent_req);
        struct req_write_state *state = tevent_req_data(
                req, struct req_write_state);
        int err;

        state->ret = writev_recv(subreq, &err);
        TALLOC_FREE(subreq);
        if (state->ret < 0) {
                tevent_req_error(req, err);
                return;
        }
        tevent_req_done(req);
}

ssize_t wb_req_write_recv(struct tevent_req *req, int *err)
{
        struct req_write_state *state = tevent_req_data(
                req, struct req_write_state);

        if (tevent_req_is_unix_error(req, err)) {
                return -1;
        }
        return state->ret;
}

struct resp_read_state {
        struct winbindd_response *wb_resp;
        ssize_t ret;
};

static ssize_t wb_resp_more(uint8_t *buf, size_t buflen, void *private_data);
static void wb_resp_read_done(struct tevent_req *subreq);

struct tevent_req *wb_resp_read_send(TALLOC_CTX *mem_ctx,
                                     struct tevent_context *ev, int fd)
{
        struct tevent_req *req, *subreq;
        struct resp_read_state *state;

        req = tevent_req_create(mem_ctx, &state, struct resp_read_state);
        if (req == NULL) {
                return NULL;
        }

        subreq = read_packet_send(state, ev, fd, 4, wb_resp_more, state);
        if (tevent_req_nomem(subreq, req)) {
                return tevent_req_post(req, ev);
        }
        tevent_req_set_callback(subreq, wb_resp_read_done, req);
        return req;
}

static ssize_t wb_resp_more(uint8_t *buf, size_t buflen, void *private_data)
{
        struct winbindd_response *resp = (struct winbindd_response *)buf;

        if (buflen == 4) {
                if (resp->length < sizeof(struct winbindd_response)) {
                        DEBUG(0, ("wb_resp_read_len: Invalid response size "
                                  "received: %d (expected at least%d)\n",
                                  (int)resp->length,
                                  (int)sizeof(struct winbindd_response)));
                        return -1;
                }
        }
        return resp->length - buflen;
}

static void wb_resp_read_done(struct tevent_req *subreq)
{
        struct tevent_req *req = tevent_req_callback_data(
                subreq, struct tevent_req);
        struct resp_read_state *state = tevent_req_data(
                req, struct resp_read_state);
        uint8_t *buf;
        int err;

        state->ret = read_packet_recv(subreq, state, &buf, &err);
        TALLOC_FREE(subreq);
        if (state->ret == -1) {
                tevent_req_error(req, err);
                return;
        }

        state->wb_resp = (struct winbindd_response *)buf;

        if (state->wb_resp->length > sizeof(struct winbindd_response)) {
                state->wb_resp->extra_data.data =
                        (char *)buf + sizeof(struct winbindd_response);
        } else {
                state->wb_resp->extra_data.data = NULL;
        }
        tevent_req_done(req);
}

ssize_t wb_resp_read_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
                          struct winbindd_response **presp, int *err)
{
        struct resp_read_state *state = tevent_req_data(
                req, struct resp_read_state);

        if (tevent_req_is_unix_error(req, err)) {
                return -1;
        }
        *presp = talloc_move(mem_ctx, &state->wb_resp);
        return state->ret;
}

struct resp_write_state {
        struct iovec iov[2];
        ssize_t ret;
};

static void wb_resp_write_done(struct tevent_req *subreq);

struct tevent_req *wb_resp_write_send(TALLOC_CTX *mem_ctx,
                                      struct tevent_context *ev,
                                      struct tevent_queue *queue, int fd,
                                      struct winbindd_response *wb_resp)
{
        struct tevent_req *req, *subreq;
        struct resp_write_state *state;
        int count = 1;

        req = tevent_req_create(mem_ctx, &state, struct resp_write_state);
        if (req == NULL) {
                return NULL;
        }

        state->iov[0].iov_base = (void *)wb_resp;
        state->iov[0].iov_len = sizeof(struct winbindd_response);

        if (wb_resp->length > sizeof(struct winbindd_response)) {
                state->iov[1].iov_base = (void *)wb_resp->extra_data.data;
                state->iov[1].iov_len =
                        wb_resp->length - sizeof(struct winbindd_response);
                count = 2;
        }

        subreq = writev_send(state, ev, queue, fd, true, state->iov, count);
        if (tevent_req_nomem(subreq, req)) {
                return tevent_req_post(req, ev);
        }
        tevent_req_set_callback(subreq, wb_resp_write_done, req);
        return req;
}

static void wb_resp_write_done(struct tevent_req *subreq)
{
        struct tevent_req *req = tevent_req_callback_data(
                subreq, struct tevent_req);
        struct resp_write_state *state = tevent_req_data(
                req, struct resp_write_state);
        int err;

        state->ret = writev_recv(subreq, &err);
        TALLOC_FREE(subreq);
        if (state->ret < 0) {
                tevent_req_error(req, err);
                return;
        }
        tevent_req_done(req);
}

ssize_t wb_resp_write_recv(struct tevent_req *req, int *err)
{
        struct resp_write_state *state = tevent_req_data(
                req, struct resp_write_state);

        if (tevent_req_is_unix_error(req, err)) {
                return -1;
        }
        return state->ret;
}

struct wb_simple_trans_state {
        struct tevent_context *ev;
        int fd;
        struct winbindd_response *wb_resp;
};

static void wb_simple_trans_write_done(struct tevent_req *subreq);
static void wb_simple_trans_read_done(struct tevent_req *subreq);

struct tevent_req *wb_simple_trans_send(TALLOC_CTX *mem_ctx,
                                        struct tevent_context *ev,
                                        struct tevent_queue *queue, int fd,
                                        struct winbindd_request *wb_req)
{
        struct tevent_req *req, *subreq;
        struct wb_simple_trans_state *state;

        req = tevent_req_create(mem_ctx, &state, struct wb_simple_trans_state);
        if (req == NULL) {
                return NULL;
        }

        wb_req->length = sizeof(struct winbindd_request);

        state->ev = ev;
        state->fd = fd;

        subreq = wb_req_write_send(state, ev, queue, fd, wb_req);
        if (tevent_req_nomem(subreq, req)) {
                return tevent_req_post(req, ev);
        }
        tevent_req_set_callback(subreq, wb_simple_trans_write_done, req);

        return req;
}

static void wb_simple_trans_write_done(struct tevent_req *subreq)
{
        struct tevent_req *req = tevent_req_callback_data(
                subreq, struct tevent_req);
        struct wb_simple_trans_state *state = tevent_req_data(
                req, struct wb_simple_trans_state);
        ssize_t ret;
        int err;

        ret = wb_req_write_recv(subreq, &err);
        TALLOC_FREE(subreq);
        if (ret == -1) {
                tevent_req_error(req, err);
                return;
        }
        subreq = wb_resp_read_send(state, state->ev, state->fd);
        if (tevent_req_nomem(subreq, req)) {
                return;
        }
        tevent_req_set_callback(subreq, wb_simple_trans_read_done, req);
}

static void wb_simple_trans_read_done(struct tevent_req *subreq)
{
        struct tevent_req *req = tevent_req_callback_data(
                subreq, struct tevent_req);
        struct wb_simple_trans_state *state = tevent_req_data(
                req, struct wb_simple_trans_state);
        ssize_t ret;
        int err;

        ret = wb_resp_read_recv(subreq, state, &state->wb_resp, &err);
        TALLOC_FREE(subreq);
        if (ret == -1) {
                tevent_req_error(req, err);
                return;
        }

        tevent_req_done(req);
}

int wb_simple_trans_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
                         struct winbindd_response **presponse, int *err)
{
        struct wb_simple_trans_state *state = tevent_req_data(
                req, struct wb_simple_trans_state);

        if (tevent_req_is_unix_error(req, err)) {
                return -1;
        }
        *presponse = talloc_move(mem_ctx, &state->wb_resp);
        return 0;
}