/*
 * 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 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <sys/types.h>
#include <sys/ctfs.h>
#include <sys/contract/process.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <fcntl.h>
#include <libcontract.h>
#include <libcontract_priv.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "dhcpagent_ipc.h"
#include "dhcpagent_util.h"

/*
 * Strings returned by dhcp_status_hdr_string() and
 * dhcp_status_reply_to_string(). The first define is the header line, and
 * the second defines line printed underneath.
 * The spacing of fields must match.
 */
#define DHCP_STATUS_HDR "Interface  State         Sent  Recv  Declined  Flags\n"
#define DHCP_STATUS_STR "%-10s %-12s %5d %5d %9d  "

static const char *time_to_string(time_t abs_time);

/*
 * dhcp_state_to_string(): given a state, provides the state's name
 *
 *    input: DHCPSTATE: the state to get the name of
 *   output: const char *: the state's name
 */

const char *
dhcp_state_to_string(DHCPSTATE state)
{
        const char *states[] = {
                "INIT",
                "SELECTING",
                "REQUESTING",
                "PRE_BOUND",
                "BOUND",
                "RENEWING",
                "REBINDING",
                "INFORMATION",
                "INIT_REBOOT",
                "ADOPTING",
                "INFORM_SENT",
                "DECLINING",
                "RELEASING"
        };

        if (state < 0 || state >= DHCP_NSTATES)
                return ("<unknown>");

        return (states[state]);
}

static int
init_template(void)
{
        int fd;
        int err = 0;

        fd = open64(CTFS_ROOT "/process/template", O_RDWR);
        if (fd == -1)
                return (-1);

        /*
         * Deliver no events, don't inherit, and allow it to be orphaned.
         */
        err |= ct_tmpl_set_critical(fd, 0);
        err |= ct_tmpl_set_informative(fd, 0);
        err |= ct_pr_tmpl_set_fatal(fd, CT_PR_EV_HWERR);
        err |= ct_pr_tmpl_set_param(fd, CT_PR_PGRPONLY | CT_PR_REGENT);
        if (err != 0 || ct_tmpl_activate(fd) != 0) {
                (void) close(fd);
                return (-1);
        }

        return (fd);
}

/*
 * dhcp_start_agent(): starts the agent if not already running
 *
 *   input: int: number of seconds to wait for agent to start (-1 is forever)
 *  output: int: 0 on success, -1 on failure
 */

int
dhcp_start_agent(int timeout)
{
        int                     error;
        time_t                  start_time = time(NULL);
        dhcp_ipc_request_t      *request;
        dhcp_ipc_reply_t        *reply;
        int                     ctfd;
        pid_t                   childpid;
        ctid_t                  ct;

        /*
         * just send a dummy request to the agent to find out if it's
         * up.  we do this instead of directly connecting to it since
         * we want to make sure we follow its IPC conventions
         * (otherwise, it will log warnings to syslog).
         */

        request = dhcp_ipc_alloc_request(DHCP_PING, "", NULL, 0,
            DHCP_TYPE_NONE);
        if (request == NULL)
                return (-1);

        error = dhcp_ipc_make_request(request, &reply, 0);
        if (error == 0) {
                free(reply);
                free(request);
                return (0);
        }
        if (error != DHCP_IPC_E_CONNECT)
                goto fail;

        if ((ctfd = init_template()) == -1)
                goto fail;

        childpid = fork();

        (void) ct_tmpl_clear(ctfd);
        (void) close(ctfd);

        switch (childpid) {
        case -1:
                goto fail;

        case  0:
                (void) execl(DHCP_AGENT_PATH, DHCP_AGENT_PATH, (char *)0);
                _exit(EXIT_FAILURE);

        default:
                break;
        }

        /* wait for the daemon to run and then abandon the contract */
        (void) waitpid(childpid, NULL, 0);

        if (contract_latest(&ct) != -1)
                (void) contract_abandon_id(ct);

        while ((timeout != -1) && (time(NULL) - start_time < timeout)) {
                error = dhcp_ipc_make_request(request, &reply, 0);
                if (error == 0) {
                        free(reply);
                        free(request);
                        return (0);
                } else if (error != DHCP_IPC_E_CONNECT)
                        break;
                (void) sleep(1);
        }

fail:
        free(request);
        return (-1);
}

/*
 * dhcp_status_hdr_string(): Return a string suitable to use as the header
 *                           when printing DHCP_STATUS reply.
 *  output: const char *: newline terminated printable string
 */
const char *
dhcp_status_hdr_string(void)
{
        return (DHCP_STATUS_HDR);
}

/*
 * time_to_string(): Utility routine for printing time
 *
 *   input: time_t *: time_t to stringify
 *  output: const char *: printable time
 */
static const char *
time_to_string(time_t abs_time)
{
        static char time_buf[24];
        time_t tm = abs_time;

        if (tm == DHCP_PERM)
                return ("Never");

        if (strftime(time_buf, sizeof (time_buf), "%m/%d/%Y %R",
            localtime(&tm)) == 0)
                return ("<unknown>");

        return (time_buf);
}

/*
 * dhcp_status_reply_to_string(): Return DHCP IPC reply of type DHCP_STATUS
 *                                as a printable string
 *
 *   input: dhcp_reply_t *: contains the status structure to print
 *  output: const char *: newline terminated printable string
 */
const char *
dhcp_status_reply_to_string(dhcp_ipc_reply_t *reply)
{
        static char str[1024];
        size_t reply_size;
        dhcp_status_t *status;

        status = dhcp_ipc_get_data(reply, &reply_size, NULL);
        if (reply_size < DHCP_STATUS_VER1_SIZE)
                return ("<Internal error: status msg size>\n");

        (void) snprintf(str, sizeof (str), DHCP_STATUS_STR,
            status->if_name, dhcp_state_to_string(status->if_state),
            status->if_sent, status->if_recv, status->if_bad_offers);

        if (status->if_dflags & DHCP_IF_PRIMARY)
                (void) strlcat(str, "[PRIMARY] ", sizeof (str));

        if (status->if_dflags & DHCP_IF_BOOTP)
                (void) strlcat(str, "[BOOTP] ", sizeof (str));

        if (status->if_dflags & DHCP_IF_FAILED)
                (void) strlcat(str, "[FAILED] ", sizeof (str));

        if (status->if_dflags & DHCP_IF_BUSY)
                (void) strlcat(str, "[BUSY] ", sizeof (str));

        if (status->if_dflags & DHCP_IF_V6)
                (void) strlcat(str, "[V6] ", sizeof (str));

        (void) strlcat(str, "\n", sizeof (str));

        switch (status->if_state) {
        case BOUND:
        case RENEWING:
        case REBINDING:
                break;
        default:
                return (str);
        }

        (void) strlcat(str, "(Began, Expires, Renew) = (", sizeof (str));
        (void) strlcat(str, time_to_string(status->if_began), sizeof (str));
        (void) strlcat(str, ", ", sizeof (str));
        (void) strlcat(str, time_to_string(status->if_lease), sizeof (str));
        (void) strlcat(str, ", ", sizeof (str));
        (void) strlcat(str, time_to_string(status->if_t1), sizeof (str));
        (void) strlcat(str, ")\n", sizeof (str));
        return (str);
}