/*
 * 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 2010 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <assert.h>
#include <auth_attr.h>
#include <auth_list.h>
#include <bsm/adt.h>
#include <bsm/adt_event.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <libgen.h>
#include <pwd.h>
#include <secdb.h>
#include <stdlib.h>
#include <sys/param.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <stdio.h>
#include <strings.h>
#include <unistd.h>

#include "libnwam_impl.h"
#include <libnwam_priv.h>
#include <libnwam.h>

/*
 * Communicate with and implement library backend (running in netcfgd) to
 * retrieve or change NWAM configuration.
 */

static int backend_door_client_fd = -1;

/*
 * Check if uid has proper auths.  flags is used to check auths for
 * enable/disable of profiles and manipulation of Known WLANs.
 */
static nwam_error_t
nwam_check_auths(uid_t uid, boolean_t write, uint64_t flags)
{
        struct passwd *pwd;
        nwam_error_t err = NWAM_SUCCESS;

        if ((pwd = getpwuid(uid)) == NULL) {
                endpwent();
                return (NWAM_PERMISSION_DENIED);
        }

        if (flags & NWAM_FLAG_ENTITY_ENABLE) {
                /* Enabling/disabling profile - need SELECT auth */
                if (chkauthattr(AUTOCONF_SELECT_AUTH, pwd->pw_name) == 0)
                        err = NWAM_PERMISSION_DENIED;

        } else if (flags & NWAM_FLAG_ENTITY_KNOWN_WLAN) {
                /* Known WLAN activity - need WLAN auth */
                if (chkauthattr(AUTOCONF_WLAN_AUTH, pwd->pw_name) == 0)
                        err = NWAM_PERMISSION_DENIED;

        } else {
                /*
                 * First, check for WRITE, since it implies READ.  If this
                 * auth is not present, and write is true, fail, otherwise
                 * check for READ.
                 */
                if (chkauthattr(AUTOCONF_WRITE_AUTH, pwd->pw_name) == 0) {
                        if (write) {
                                err = NWAM_PERMISSION_DENIED;
                        } else {
                                if (chkauthattr(AUTOCONF_READ_AUTH,
                                    pwd->pw_name) == 0)
                                        err = NWAM_PERMISSION_DENIED;
                        }
                }
        }

        endpwent();
        return (err);
}

static nwam_error_t
nwam_create_backend_door_arg(nwam_backend_door_cmd_t cmd,
    const char *dbname, const char *objname, uint64_t flags,
    void *obj, nwam_backend_door_arg_t *arg)
{
        nwam_error_t err;
        size_t datalen = 0;
        caddr_t dataptr;

        switch (cmd) {
        case NWAM_BACKEND_DOOR_CMD_READ_REQ:
                /*
                 * For a read request,  we want the full buffer to be
                 * available for the backend door to write to.
                 */
                datalen = NWAM_BACKEND_DOOR_ARG_SIZE;
                break;

        case NWAM_BACKEND_DOOR_CMD_UPDATE_REQ:
                /*
                 * An update request may either specify an object list
                 * (which we pack into the buffer immediately after the
                 * backend door request) or may not specify an object
                 * (signifying a request to create the container of the
                 * object).
                 */
                if (obj == NULL) {
                        datalen = 0;
                        break;
                }
                /* Data immediately follows the descriptor */
                dataptr = (caddr_t)arg + sizeof (nwam_backend_door_arg_t);
                datalen = NWAM_BACKEND_DOOR_ARG_SIZE;
                /* pack object list for update request,  adjusting datalen */
                if ((err = nwam_pack_object_list(obj, (char **)&dataptr,
                    &datalen)) != NWAM_SUCCESS)
                        return (err);
                break;

        case NWAM_BACKEND_DOOR_CMD_REMOVE_REQ:
                /* A remove request has no associated object list. */
                datalen = 0;
                break;

        default:
                return (NWAM_INVALID_ARG);
        }

        arg->nwbda_cmd = cmd;
        arg->nwbda_flags = flags;
        arg->nwbda_datalen = datalen;
        arg->nwbda_result = NWAM_SUCCESS;

        if (dbname != NULL)
                (void) strlcpy(arg->nwbda_dbname, dbname, MAXPATHLEN);
        else
                arg->nwbda_dbname[0] = '\0';

        if (objname != NULL)
                (void) strlcpy(arg->nwbda_object, objname, NWAM_MAX_NAME_LEN);
        else
                arg->nwbda_object[0] = '\0';

        return (NWAM_SUCCESS);
}

/*
 * If the arg datalen is non-zero,  unpack the object list associated with
 * the backend door argument.
 */
static nwam_error_t
nwam_read_object_from_backend_door_arg(nwam_backend_door_arg_t *arg,
    char *dbname, char *name, void *objp)
{
        nwam_error_t err;
        caddr_t dataptr = (caddr_t)arg + sizeof (nwam_backend_door_arg_t);

        if (arg->nwbda_result != NWAM_SUCCESS)
                return (arg->nwbda_result);

        if (arg->nwbda_datalen > 0) {
                if ((err = nwam_unpack_object_list((char *)dataptr,
                    arg->nwbda_datalen, objp)) != NWAM_SUCCESS)
                        return (err);
        } else {
                *((char **)objp) = NULL;
        }

        /*
         * If "dbname" and "name" are non-NULL, copy in the actual dbname
         * and name values from the door arg since both may have been changed
         * from case-insensitive to case-sensitive matches.  They will be the
         * same length as they only differ in case.
         */
        if (dbname != NULL && strcmp(dbname, arg->nwbda_dbname) != 0)
                (void) strlcpy(dbname, arg->nwbda_dbname, strlen(dbname) + 1);
        if (name != NULL && strcmp(name, arg->nwbda_object) != 0)
                (void) strlcpy(name, arg->nwbda_object, strlen(name) + 1);

        return (NWAM_SUCCESS);
}

/* ARGSUSED */
void
nwam_backend_door_server(void *cookie, char *arg, size_t arg_size,
    door_desc_t *dp, uint_t ndesc)
{
        /* LINTED: alignment */
        nwam_backend_door_arg_t *req = (nwam_backend_door_arg_t *)arg;
        nwam_error_t err;
        void *obj, *newobj = NULL;
        ucred_t *ucr = NULL;
        uid_t uid;
        boolean_t write = B_TRUE;

        /* Check arg size */
        if (arg_size < sizeof (nwam_backend_door_arg_t)) {
                req->nwbda_result = NWAM_INVALID_ARG;
                (void) door_return((char *)req,
                    sizeof (nwam_backend_door_arg_t), NULL, 0);
        }

        if (door_ucred(&ucr) != 0) {
                req->nwbda_result = NWAM_ERROR_INTERNAL;
                (void) door_return((char *)req, arg_size, NULL, 0);
        }

        /* Check auths */
        uid = ucred_getruid(ucr);

        if (req->nwbda_cmd == NWAM_BACKEND_DOOR_CMD_READ_REQ)
                write = B_FALSE;
        if ((err = nwam_check_auths(uid, write, req->nwbda_flags))
            != NWAM_SUCCESS) {
                if (write) {
                        nwam_record_audit_event(ucr,
                            req->nwbda_cmd == NWAM_BACKEND_DOOR_CMD_UPDATE_REQ ?
                            ADT_netcfg_update : ADT_netcfg_remove,
                            (char *)req->nwbda_object,
                            (char *)req->nwbda_dbname, ADT_FAILURE,
                            ADT_FAIL_VALUE_AUTH);
                }
                req->nwbda_result = err;
                goto door_return;
        }

        switch (req->nwbda_cmd) {
        case NWAM_BACKEND_DOOR_CMD_READ_REQ:
                if ((req->nwbda_result = nwam_read_object_from_files_backend
                    (strlen(req->nwbda_dbname) > 0 ? req->nwbda_dbname : NULL,
                    strlen(req->nwbda_object) > 0 ? req->nwbda_object : NULL,
                    req->nwbda_flags, &newobj)) != NWAM_SUCCESS) {
                        break;
                }
                if (newobj != NULL) {
                        size_t datalen = arg_size -
                            sizeof (nwam_backend_door_arg_t);
                        caddr_t dataptr = (caddr_t)req +
                            sizeof (nwam_backend_door_arg_t);

                        if ((req->nwbda_result = nwam_pack_object_list(newobj,
                            (char **)&dataptr, &datalen)) != NWAM_SUCCESS)
                                req->nwbda_datalen = 0;
                        else
                                req->nwbda_datalen = datalen;
                        nwam_free_object_list(newobj);
                } else {
                        req->nwbda_datalen = 0;
                }
                break;

        case NWAM_BACKEND_DOOR_CMD_UPDATE_REQ:
                if (req->nwbda_datalen == 0) {
                        obj = NULL;
                } else {
                        if ((req->nwbda_result =
                            nwam_read_object_from_backend_door_arg
                            (req, NULL, NULL, &obj)) != NWAM_SUCCESS)
                                break;
                }
                req->nwbda_result = nwam_update_object_in_files_backend(
                    req->nwbda_dbname[0] == 0 ? NULL : req->nwbda_dbname,
                    req->nwbda_object[0] == 0 ? NULL : req->nwbda_object,
                    req->nwbda_flags, obj);
                nwam_free_object_list(obj);
                if (req->nwbda_result == NWAM_SUCCESS) {
                        req->nwbda_datalen = 0;
                        nwam_record_audit_event(ucr, ADT_netcfg_update,
                            (char *)req->nwbda_object,
                            (char *)req->nwbda_dbname, ADT_SUCCESS,
                            ADT_SUCCESS);
                }
                break;

        case NWAM_BACKEND_DOOR_CMD_REMOVE_REQ:
                req->nwbda_result = nwam_remove_object_from_files_backend
                    (strlen(req->nwbda_dbname) > 0 ? req->nwbda_dbname : NULL,
                    strlen(req->nwbda_object) > 0 ? req->nwbda_object : NULL,
                    req->nwbda_flags);
                if (req->nwbda_result == NWAM_SUCCESS) {
                        nwam_record_audit_event(ucr, ADT_netcfg_update,
                            (char *)req->nwbda_object,
                            (char *)req->nwbda_dbname, ADT_SUCCESS,
                            ADT_SUCCESS);
                }
                break;

        default:
                req->nwbda_result = NWAM_INVALID_ARG;
                break;
        }

door_return:
        ucred_free(ucr);

        (void) door_return((char *)req, arg_size, NULL, 0);
}

static int backend_door_fd = -1;

void
nwam_backend_fini(void)
{
        if (backend_door_fd != -1) {
                (void) door_revoke(backend_door_fd);
                backend_door_fd = -1;
        }
        (void) unlink(NWAM_BACKEND_DOOR_FILE);
}

nwam_error_t
nwam_backend_init(void)
{
        int did;
        struct stat statbuf;

        /* Create the door directory if it doesn't already exist */
        if (stat(NWAM_DOOR_DIR, &statbuf) < 0) {
                if (mkdir(NWAM_DOOR_DIR, (mode_t)0755) < 0)
                        return (NWAM_ERROR_BACKEND_INIT);
        } else {
                if ((statbuf.st_mode & S_IFMT) != S_IFDIR)
                        return (NWAM_ERROR_BACKEND_INIT);
        }

        if (chmod(NWAM_DOOR_DIR, 0755) < 0 ||
            chown(NWAM_DOOR_DIR, UID_NETADM, GID_NETADM) < 0)
                return (NWAM_ERROR_BACKEND_INIT);

        /* Do a low-overhead "touch" on the file that will be the door node. */
        did = open(NWAM_BACKEND_DOOR_FILE,
            O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW | O_NONBLOCK,
            S_IRUSR | S_IRGRP | S_IROTH);

        if (did != -1)
                (void) close(did);
        else if (errno != EEXIST)
                return (NWAM_ERROR_BACKEND_INIT);

        /* Create the door. */
        backend_door_fd = door_create(nwam_backend_door_server, NULL,
            DOOR_REFUSE_DESC);
        if (backend_door_fd == -1)
                return (NWAM_ERROR_BACKEND_INIT);

        /* Attach the door to the file. */
        (void) fdetach(NWAM_BACKEND_DOOR_FILE);
        if (fattach(backend_door_fd, NWAM_BACKEND_DOOR_FILE) == -1) {
                (void) door_revoke(backend_door_fd);
                return (NWAM_ERROR_BACKEND_INIT);
        }

        return (NWAM_SUCCESS);
}

static nwam_error_t
nwam_backend_door_call(nwam_backend_door_cmd_t cmd, char *dbname,
    char *objname, uint64_t flags, void *obj)
{
        uchar_t reqbuf[NWAM_BACKEND_DOOR_ARG_SIZE];
        /* LINTED: alignment */
        nwam_backend_door_arg_t *req = (nwam_backend_door_arg_t *)&reqbuf;
        nwam_error_t err, reserr;

        if ((err = nwam_create_backend_door_arg(cmd, dbname, objname, flags,
            obj, req)) != NWAM_SUCCESS)
                return (err);

        if (nwam_make_door_call(NWAM_BACKEND_DOOR_FILE, &backend_door_client_fd,
            req, sizeof (reqbuf)) != 0)
                return (NWAM_ERROR_BIND);

        reserr = req->nwbda_result;

        if (cmd == NWAM_BACKEND_DOOR_CMD_READ_REQ) {
                err = nwam_read_object_from_backend_door_arg(req, dbname,
                    objname, obj);
        }

        return (err == NWAM_SUCCESS ? reserr : err);
}

/*
 * Read object specified by objname from backend dbname, retrieving an object
 * list representation.
 *
 * If dbname is NULL, obj is a list of string arrays consisting of the list
 * of backend dbnames.
 *
 * If objname is NULL, read all objects in the specified dbname and create
 * an object list containing a string array which represents each object.
 *
 * Otherwise obj will point to a list of the properties for the object
 * specified by objname in the backend dbname.
 */
/* ARGSUSED2 */
nwam_error_t
nwam_read_object_from_backend(char *dbname, char *objname,
    uint64_t flags, void *obj)
{
        nwam_error_t err = nwam_check_auths(getuid(), B_FALSE, flags);

        if (err != NWAM_SUCCESS)
                return (err);

        return (nwam_backend_door_call(NWAM_BACKEND_DOOR_CMD_READ_REQ,
            dbname, objname, flags, obj));
}

/*
 * Read in all objects from backend dbname and update object corresponding
 * to objname with properties recorded in proplist, writing the results to
 * the backend dbname.
 */
nwam_error_t
nwam_update_object_in_backend(char *dbname, char *objname,
    uint64_t flags, void *obj)
{
        nwam_error_t err = nwam_check_auths(getuid(), B_TRUE, flags);

        if (err != NWAM_SUCCESS)
                return (err);

        return (nwam_backend_door_call(NWAM_BACKEND_DOOR_CMD_UPDATE_REQ,
            dbname, objname, flags, obj));
}

/*
 * Remove specified object from backend by reading in the list of objects,
 * removing objname and writing the remainder.
 *
 * If objname is NULL, remove the backend dbname.
 */
nwam_error_t
nwam_remove_object_from_backend(char *dbname, char *objname, uint64_t flags)
{
        nwam_error_t err = nwam_check_auths(getuid(), B_TRUE, flags);

        if (err != NWAM_SUCCESS)
                return (err);

        return (nwam_backend_door_call(NWAM_BACKEND_DOOR_CMD_REMOVE_REQ,
            dbname, objname, flags, NULL));
}