svc/configd/object.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

/*
 * This file only contains the transaction commit logic.
 */

#include <assert.h>
#include <alloca.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <sys/sysmacros.h>
#include "configd.h"

#define INVALID_OBJ_ID ((uint32_t)-1)
#define INVALID_TYPE ((uint32_t)-1)

struct tx_cmd {
    const struct rep_protocol_transaction_cmd *tx_cmd;
    const char  *tx_prop;
    uint32_t    *tx_values;
    uint32_t    tx_nvalues;
    uint32_t    tx_orig_value_id;
    char        tx_found;
    char        tx_processed;
    char        tx_bad;
};

static int
tx_cmd_compare(const void *key, const void *elem_arg)
{
    const struct tx_cmd *elem = elem_arg;

    return (strcmp((const char *)key, elem->tx_prop));
}

struct tx_commit_data {
    uint32_t    txc_pg_id;
    uint32_t    txc_gen;
    uint32_t    txc_oldgen;
    short       txc_backend;
    backend_tx_t    *txc_tx;
    backend_query_t *txc_inserts;
    size_t      txc_count;
    rep_protocol_responseid_t txc_result;
    struct tx_cmd   txc_cmds[1];        /* actually txc_count */
};
#define TX_COMMIT_DATA_SIZE(count) \
    offsetof(struct tx_commit_data, txc_cmds[count])

/*ARGSUSED*/
static int
tx_check_genid(void *data_arg, int columns, char **vals, char **names)
{
    tx_commit_data_t *data = data_arg;
    assert(columns == 1);
    if (atoi(vals[0]) != data->txc_oldgen)
        data->txc_result = REP_PROTOCOL_FAIL_NOT_LATEST;
    else
        data->txc_result = REP_PROTOCOL_SUCCESS;
    return (BACKEND_CALLBACK_CONTINUE);
}

/*
 * tx_process_property() is called once for each property in current
 * property group generation.  Its purpose is threefold:
 *
 *  1. copy properties not mentioned in the transaction over unchanged.
 *  2. mark DELETEd properties as seen (they will be left out of the new
 *     generation).
 *  3. consistancy-check NEW, CLEAR, and REPLACE commands.
 *
 * Any consistancy problems set tx_bad, and seen properties are marked
 * tx_found.  These is used later, in tx_process_cmds().
 */
/*ARGSUSED*/
static int
tx_process_property(void *data_arg, int columns, char **vals, char **names)
{
    tx_commit_data_t *data = data_arg;
    struct tx_cmd *elem;

    const char *prop_name = vals[0];
    const char *prop_type = vals[1];
    const char *lnk_val_id = vals[2];

    char *endptr;

    assert(columns == 3);

    elem = bsearch(prop_name, data->txc_cmds, data->txc_count,
        sizeof (*data->txc_cmds), tx_cmd_compare);

    if (elem == NULL) {
        backend_query_add(data->txc_inserts,
            "INSERT INTO prop_lnk_tbl"
            "    (lnk_pg_id, lnk_gen_id, lnk_prop_name, lnk_prop_type,"
            "    lnk_val_id) "
            "VALUES ( %d, %d, '%q', '%q', %Q );",
            data->txc_pg_id, data->txc_gen, prop_name, prop_type,
            lnk_val_id);
    } else {
        assert(!elem->tx_found);
        elem->tx_found = 1;

        if (lnk_val_id != NULL) {
            errno = 0;
            elem->tx_orig_value_id =
                strtoul(lnk_val_id, &endptr, 10);
            if (elem->tx_orig_value_id == 0 || *endptr != 0 ||
                errno != 0) {
                return (BACKEND_CALLBACK_ABORT);
            }
        } else {
            elem->tx_orig_value_id = 0;
        }

        switch (elem->tx_cmd->rptc_action) {
        case REP_PROTOCOL_TX_ENTRY_NEW:
            elem->tx_bad = 1;
            data->txc_result = REP_PROTOCOL_FAIL_EXISTS;
            break;
        case REP_PROTOCOL_TX_ENTRY_CLEAR:
            if (REP_PROTOCOL_BASE_TYPE(elem->tx_cmd->rptc_type) !=
                prop_type[0] &&
                REP_PROTOCOL_SUBTYPE(elem->tx_cmd->rptc_type) !=
                prop_type[1]) {
                elem->tx_bad = 1;
                data->txc_result =
                    REP_PROTOCOL_FAIL_TYPE_MISMATCH;
            }
            break;
        case REP_PROTOCOL_TX_ENTRY_REPLACE:
            break;
        case REP_PROTOCOL_TX_ENTRY_DELETE:
            elem->tx_processed = 1;
            break;
        default:
            assert(0);
            break;
        }
    }
    return (BACKEND_CALLBACK_CONTINUE);
}

/*
 * tx_process_cmds() finishes the job tx_process_property() started:
 *
 *  1. if tx_process_property() marked a command as bad, we skip it.
 *  2. if a DELETE, REPLACE, or CLEAR operated on a non-existant property,
 *      we mark it as bad.
 *  3. we complete the work of NEW, REPLACE, and CLEAR, by inserting the
 *      appropriate values into the database.
 *  4. we delete all replaced data, if it is no longer referenced.
 *
 * Finally, we check all of the commands, and fail if anything was marked bad.
 */
static int
tx_process_cmds(tx_commit_data_t *data)
{
    int idx;
    int r;
    int count = data->txc_count;
    struct tx_cmd *elem;
    uint32_t val_id = 0;
    uint8_t type[3];

    backend_query_t *q;
    int do_delete;

    /*
     * For persistent pgs, we use backend_fail_if_seen to abort the
     * deletion if there is a snapshot using our current state.
     *
     * All of the deletions in this function are safe, since
     * rc_tx_commit() guarantees that all the data is in-cache.
     */
    q = backend_query_alloc();

    if (data->txc_backend != BACKEND_TYPE_NONPERSIST) {
        backend_query_add(q,
            "SELECT 1 FROM snaplevel_lnk_tbl "
            "    WHERE (snaplvl_pg_id = %d AND snaplvl_gen_id = %d); ",
            data->txc_pg_id, data->txc_oldgen);
    }
    backend_query_add(q,
        "DELETE FROM prop_lnk_tbl"
        "    WHERE (lnk_pg_id = %d AND lnk_gen_id = %d)",
        data->txc_pg_id, data->txc_oldgen);
    r = backend_tx_run(data->txc_tx, q, backend_fail_if_seen, NULL);
    backend_query_free(q);

    if (r == REP_PROTOCOL_SUCCESS)
        do_delete = 1;
    else if (r == REP_PROTOCOL_DONE)
        do_delete = 0;      /* old gen_id is in use */
    else
        return (r);

    for (idx = 0; idx < count; idx++) {
        elem = &data->txc_cmds[idx];

        if (elem->tx_bad)
            continue;

        switch (elem->tx_cmd->rptc_action) {
        case REP_PROTOCOL_TX_ENTRY_DELETE:
        case REP_PROTOCOL_TX_ENTRY_REPLACE:
        case REP_PROTOCOL_TX_ENTRY_CLEAR:
            if (!elem->tx_found) {
                elem->tx_bad = 1;
                continue;
            }
            break;
        case REP_PROTOCOL_TX_ENTRY_NEW:
            break;
        default:
            assert(0);
            break;
        }

        if (do_delete &&
            elem->tx_cmd->rptc_action != REP_PROTOCOL_TX_ENTRY_NEW &&
            elem->tx_orig_value_id != 0) {
            /*
             * delete the old values, if they are not in use
             */
            q = backend_query_alloc();
            backend_query_add(q,
                "SELECT 1 FROM prop_lnk_tbl "
                "    WHERE (lnk_val_id = %d); "
                "DELETE FROM value_tbl"
                "    WHERE (value_id = %d)",
                elem->tx_orig_value_id, elem->tx_orig_value_id);
            r = backend_tx_run(data->txc_tx, q,
                backend_fail_if_seen, NULL);
            backend_query_free(q);
            if (r != REP_PROTOCOL_SUCCESS && r != REP_PROTOCOL_DONE)
                return (r);
        }

        if (elem->tx_cmd->rptc_action == REP_PROTOCOL_TX_ENTRY_DELETE)
            continue;       /* no further work to do */

        type[0] = REP_PROTOCOL_BASE_TYPE(elem->tx_cmd->rptc_type);
        type[1] = REP_PROTOCOL_SUBTYPE(elem->tx_cmd->rptc_type);
        type[2] = 0;

        if (elem->tx_nvalues == 0) {
            r = backend_tx_run_update(data->txc_tx,
                "INSERT INTO prop_lnk_tbl"
                "    (lnk_pg_id, lnk_gen_id, "
                "    lnk_prop_name, lnk_prop_type, lnk_val_id) "
                "VALUES ( %d, %d, '%q', '%q', NULL );",
                data->txc_pg_id, data->txc_gen, elem->tx_prop,
                type);
        } else {
            uint32_t *v, i = 0;
            const char *str;

            val_id = backend_new_id(data->txc_tx, BACKEND_ID_VALUE);
            if (val_id == 0)
                return (REP_PROTOCOL_FAIL_NO_RESOURCES);
            r = backend_tx_run_update(data->txc_tx,
                "INSERT INTO prop_lnk_tbl "
                "    (lnk_pg_id, lnk_gen_id, "
                "    lnk_prop_name, lnk_prop_type, lnk_val_id) "
                "VALUES ( %d, %d, '%q', '%q', %d );",
                data->txc_pg_id, data->txc_gen, elem->tx_prop,
                type, val_id);

            v = elem->tx_values;

            for (i = 0; i < elem->tx_nvalues; i++) {
                str = (const char *)&v[1];

                /*
                 * Update values in backend,  imposing
                 * ordering via the value_order column.
                 * This ordering is then used in subseqent
                 * value retrieval operations.  We can
                 * safely assume that the repository schema
                 * has been upgraded (and hence has the
                 * value_order column in value_tbl),  since
                 * it is upgraded as soon as the repository
                 * is writable.
                 */
                r = backend_tx_run_update(data->txc_tx,
                    "INSERT INTO value_tbl (value_id, "
                    "value_type, value_value, "
                    "value_order) VALUES (%d, '%c', "
                    "'%q', '%d');\n",
                    val_id, elem->tx_cmd->rptc_type,
                    str, i);
                if (r != REP_PROTOCOL_SUCCESS)
                    break;

                /*LINTED alignment*/
                v = (uint32_t *)((caddr_t)str + TX_SIZE(*v));
            }
        }
        if (r != REP_PROTOCOL_SUCCESS)
            return (REP_PROTOCOL_FAIL_UNKNOWN);
        elem->tx_processed = 1;
    }

    for (idx = 0; idx < count; idx++) {
        elem = &data->txc_cmds[idx];

        if (elem->tx_bad)
            return (REP_PROTOCOL_FAIL_BAD_TX);
    }
    return (REP_PROTOCOL_SUCCESS);
}

static boolean_t
check_string(uintptr_t loc, uint32_t len, uint32_t sz)
{
    const char *ptr = (const char *)loc;

    if (len == 0 || len > sz || ptr[len - 1] != 0 || strlen(ptr) != len - 1)
        return (0);
    return (1);
}

static int
tx_check_and_setup(tx_commit_data_t *data, const void *cmds_arg,
    uint32_t count)
{
    const struct rep_protocol_transaction_cmd *cmds;
    struct tx_cmd *cur;
    struct tx_cmd *prev = NULL;

    uintptr_t loc;
    uint32_t sz, len;
    int idx;

    loc = (uintptr_t)cmds_arg;

    for (idx = 0; idx < count; idx++) {
        cur = &data->txc_cmds[idx];

        cmds = (struct rep_protocol_transaction_cmd *)loc;
        cur->tx_cmd = cmds;

        sz = cmds->rptc_size;

        loc += REP_PROTOCOL_TRANSACTION_CMD_MIN_SIZE;
        sz -= REP_PROTOCOL_TRANSACTION_CMD_MIN_SIZE;

        len = cmds->rptc_name_len;
        if (len <= 1 || !check_string(loc, len, sz)) {
            return (REP_PROTOCOL_FAIL_BAD_REQUEST);
        }
        cur->tx_prop = (const char *)loc;

        len = TX_SIZE(len);
        loc += len;
        sz -= len;

        cur->tx_nvalues = 0;
        cur->tx_values = (uint32_t *)loc;

        while (sz > 0) {
            if (sz < sizeof (uint32_t))
                return (REP_PROTOCOL_FAIL_BAD_REQUEST);

            cur->tx_nvalues++;

            len = *(uint32_t *)loc;
            loc += sizeof (uint32_t);
            sz -= sizeof (uint32_t);

            if (!check_string(loc, len, sz))
                return (REP_PROTOCOL_FAIL_BAD_REQUEST);

            /*
             * XXX here, we should be checking that the values
             * match the purported type
             */

            len = TX_SIZE(len);

            if (len > sz)
                return (REP_PROTOCOL_FAIL_BAD_REQUEST);

            loc += len;
            sz -= len;
        }

        if (prev != NULL && strcmp(prev->tx_prop, cur->tx_prop) >= 0)
            return (REP_PROTOCOL_FAIL_BAD_REQUEST);

        prev = cur;
    }
    return (REP_PROTOCOL_SUCCESS);
}

/*
 * Free the memory associated with a tx_commit_data structure.
 */
void
tx_commit_data_free(tx_commit_data_t *tx_data)
{
    uu_free(tx_data);
}

/*
 * Parse the data of a REP_PROTOCOL_PROPERTYGRP_TX_COMMIT message into a
 * more useful form.  The data in the message will be represented by a
 * tx_commit_data_t structure which is allocated by this function.  The
 * address of the allocated structure is returned to *tx_data and must be
 * freed by calling tx_commit_data_free().
 *
 * Parameters:
 *  cmds_arg    Address of the commands in the
 *          REP_PROTOCOL_PROPERTYGRP_TX_COMMIT message.
 *
 *  cmds_sz     Number of message bytes at cmds_arg.
 *
 *  tx_data     Points to the place to receive the address of the
 *          allocated memory.
 *
 * Fails with
 *  _BAD_REQUEST
 *  _NO_RESOURCES
 */
int
tx_commit_data_new(const void *cmds_arg, size_t cmds_sz,
    tx_commit_data_t **tx_data)
{
    const struct rep_protocol_transaction_cmd *cmds;
    tx_commit_data_t *data;
    uintptr_t loc;
    uint32_t count;
    uint32_t sz;
    int ret;

    /*
     * First, verify that the reported sizes make sense, and count
     * the number of commands.
     */
    count = 0;
    loc = (uintptr_t)cmds_arg;

    while (cmds_sz > 0) {
        cmds = (struct rep_protocol_transaction_cmd *)loc;

        if (cmds_sz <= REP_PROTOCOL_TRANSACTION_CMD_MIN_SIZE)
            return (REP_PROTOCOL_FAIL_BAD_REQUEST);

        sz = cmds->rptc_size;
        if (sz <= REP_PROTOCOL_TRANSACTION_CMD_MIN_SIZE)
            return (REP_PROTOCOL_FAIL_BAD_REQUEST);

        sz = TX_SIZE(sz);
        if (sz > cmds_sz)
            return (REP_PROTOCOL_FAIL_BAD_REQUEST);

        loc += sz;
        cmds_sz -= sz;
        count++;
    }

    data = uu_zalloc(TX_COMMIT_DATA_SIZE(count));
    if (data == NULL)
        return (REP_PROTOCOL_FAIL_NO_RESOURCES);

    /*
     * verify that everything looks okay, and set up our command
     * datastructures.
     */
    data->txc_count = count;
    ret = tx_check_and_setup(data, cmds_arg, count);
    if (ret == REP_PROTOCOL_SUCCESS) {
        *tx_data = data;
    } else {
        *tx_data = NULL;
        uu_free(data);
    }
    return (ret);
}

/*
 * The following are a set of accessor functions to retrieve data from a
 * tx_commit_data_t that has been allocated by tx_commit_data_new().
 */

/*
 * Return the action of the transaction command whose command number is
 * cmd_no.  The action is placed at *action.
 *
 * Returns:
 *  _FAIL_BAD_REQUEST   cmd_no is out of range.
 */
int
tx_cmd_action(tx_commit_data_t *tx_data, size_t cmd_no,
    enum rep_protocol_transaction_action *action)
{
    struct tx_cmd *cur;

    assert(cmd_no < tx_data->txc_count);
    if (cmd_no >= tx_data->txc_count)
        return (REP_PROTOCOL_FAIL_BAD_REQUEST);

    cur = &tx_data->txc_cmds[cmd_no];
    *action = cur->tx_cmd->rptc_action;
    return (REP_PROTOCOL_SUCCESS);
}

/*
 * Return the number of transaction commands held in tx_data.
 */
size_t
tx_cmd_count(tx_commit_data_t *tx_data)
{
    return (tx_data->txc_count);
}

/*
 * Return the number of property values that are associated with the
 * transaction command whose number is cmd_no.  The number of values is
 * returned to *nvalues.
 *
 * Returns:
 *  _FAIL_BAD_REQUEST   cmd_no is out of range.
 */
int
tx_cmd_nvalues(tx_commit_data_t *tx_data, size_t cmd_no, uint32_t *nvalues)
{
    struct tx_cmd *cur;

    assert(cmd_no < tx_data->txc_count);
    if (cmd_no >= tx_data->txc_count)
        return (REP_PROTOCOL_FAIL_BAD_REQUEST);

    cur = &tx_data->txc_cmds[cmd_no];
    *nvalues = cur->tx_nvalues;
    return (REP_PROTOCOL_SUCCESS);
}

/*
 * Return a pointer to the property name of the command whose number is
 * cmd_no.  The property name pointer is returned to *pname.
 *
 * Returns:
 *  _FAIL_BAD_REQUEST   cmd_no is out of range.
 */
int
tx_cmd_prop(tx_commit_data_t *tx_data, size_t cmd_no, const char **pname)
{
    struct tx_cmd *cur;

    assert(cmd_no < tx_data->txc_count);
    if (cmd_no >= tx_data->txc_count)
        return (REP_PROTOCOL_FAIL_BAD_REQUEST);

    cur = &tx_data->txc_cmds[cmd_no];
    *pname = cur->tx_prop;
    return (REP_PROTOCOL_SUCCESS);
}

/*
 * Return the property type of the property whose command number is
 * cmd_no.  The property type is returned to *ptype.
 *
 * Returns:
 *  _FAIL_BAD_REQUEST   cmd_no is out of range.
 */
int
tx_cmd_prop_type(tx_commit_data_t *tx_data, size_t cmd_no, uint32_t *ptype)
{
    struct tx_cmd *cur;

    assert(cmd_no < tx_data->txc_count);
    if (cmd_no >= tx_data->txc_count)
        return (REP_PROTOCOL_FAIL_BAD_REQUEST);

    cur = &tx_data->txc_cmds[cmd_no];
    *ptype = cur->tx_cmd->rptc_type;
    return (REP_PROTOCOL_SUCCESS);
}

/*
 * This function is used to retrieve a property value from the transaction
 * data.  val_no specifies which value is to be retrieved from the
 * transaction command whose number is cmd_no.  A pointer to the specified
 * value is placed in *val.
 *
 * Returns:
 *  _FAIL_BAD_REQUEST   cmd_no or val_no is out of range.
 */
int
tx_cmd_value(tx_commit_data_t *tx_data, size_t cmd_no, uint32_t val_no,
    const char **val)
{
    const char *bp;
    struct tx_cmd *cur;
    uint32_t i;
    uint32_t value_len;

    assert(cmd_no < tx_data->txc_count);
    if (cmd_no >= tx_data->txc_count)
        return (REP_PROTOCOL_FAIL_BAD_REQUEST);

    cur = &tx_data->txc_cmds[cmd_no];
    assert(val_no < cur->tx_nvalues);
    if (val_no >= cur->tx_nvalues)
        return (REP_PROTOCOL_FAIL_BAD_REQUEST);

    /* Find the correct value */
    bp = (char *)cur->tx_values;
    for (i = 0; i < val_no; i++) {
        /* LINTED alignment */
        value_len = *(uint32_t *)bp;
        bp += sizeof (uint32_t) + TX_SIZE(value_len);
    }

    /* Bypass the count & return pointer to value. */
    bp += sizeof (uint32_t);
    *val = bp;
    return (REP_PROTOCOL_SUCCESS);
}

int
object_tx_commit(rc_node_lookup_t *lp, tx_commit_data_t *data, uint32_t *gen)
{
    uint32_t new_gen;
    int ret;
    rep_protocol_responseid_t r;
    backend_tx_t *tx;
    backend_query_t *q;
    int backend = lp->rl_backend;

    ret = backend_tx_begin(backend, &tx);
    if (ret != REP_PROTOCOL_SUCCESS)
        return (ret);

    /* Make sure the pg is up-to-date. */
    data->txc_oldgen = *gen;
    data->txc_backend = backend;
    data->txc_result = REP_PROTOCOL_FAIL_NOT_FOUND;

    q = backend_query_alloc();
    backend_query_add(q, "SELECT pg_gen_id FROM pg_tbl WHERE (pg_id = %d);",
        lp->rl_main_id);
    r = backend_tx_run(tx, q, tx_check_genid, data);
    backend_query_free(q);

    if (r != REP_PROTOCOL_SUCCESS ||
        (r = data->txc_result) != REP_PROTOCOL_SUCCESS) {
        backend_tx_rollback(tx);
        goto end;
    }

    /* If the transaction is empty, cut out early. */
    if (data->txc_count == 0) {
        backend_tx_rollback(tx);
        r = REP_PROTOCOL_DONE;
        goto end;
    }

    new_gen = backend_new_id(tx, BACKEND_ID_GENERATION);
    if (new_gen == 0) {
        backend_tx_rollback(tx);
        return (REP_PROTOCOL_FAIL_NO_RESOURCES);
    }

    data->txc_pg_id = lp->rl_main_id;
    data->txc_gen = new_gen;
    data->txc_tx = tx;

    r = backend_tx_run_update(tx,
        "UPDATE pg_tbl SET pg_gen_id = %d "
        "    WHERE (pg_id = %d AND pg_gen_id = %d);",
        new_gen, lp->rl_main_id, *gen);

    if (r != REP_PROTOCOL_SUCCESS) {
        backend_tx_rollback(tx);
        goto end;
    }

    q = backend_query_alloc();

    backend_query_add(q,
        "SELECT lnk_prop_name, lnk_prop_type, lnk_val_id "
        "FROM prop_lnk_tbl "
        "WHERE (lnk_pg_id = %d AND lnk_gen_id = %d)",
        lp->rl_main_id, *gen);

    data->txc_inserts = backend_query_alloc();
    r = backend_tx_run(tx, q, tx_process_property, data);
    backend_query_free(q);

    if (r == REP_PROTOCOL_DONE)
        r = REP_PROTOCOL_FAIL_UNKNOWN;      /* corruption */

    if (r != REP_PROTOCOL_SUCCESS ||
        (r = data->txc_result) != REP_PROTOCOL_SUCCESS) {
        backend_query_free(data->txc_inserts);
        backend_tx_rollback(tx);
        goto end;
    }

    r = backend_tx_run(tx, data->txc_inserts, NULL, NULL);
    backend_query_free(data->txc_inserts);

    if (r != REP_PROTOCOL_SUCCESS) {
        backend_tx_rollback(tx);
        goto end;
    }

    r = tx_process_cmds(data);
    if (r != REP_PROTOCOL_SUCCESS) {
        backend_tx_rollback(tx);
        goto end;
    }
    r = backend_tx_commit(tx);

    if (r == REP_PROTOCOL_SUCCESS)
        *gen = new_gen;
end:
    return (r);
}