libdhcpagent/common/dhcpagent_util.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 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);
}