/*
 * 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 (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
 */

#include <assert.h>
#include <sys/types.h>
#include <sys/acctctl.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <libintl.h>
#include <string.h>
#include <stdlib.h>
#include <stdarg.h>
#include <stdio.h>
#include <strings.h>
#include <unistd.h>
#include <errno.h>
#include <exacct.h>
#include <fcntl.h>
#include <priv.h>

#include "utils.h"

static char PNAME_FMT[] = "%s: ";
static char ERRNO_FMT[] = ": %s\n";

static char *pname;

/*PRINTFLIKE1*/
void
warn(const char *format, ...)
{
        int err = errno;
        va_list alist;
        if (pname != NULL)
                (void) fprintf(stderr, gettext(PNAME_FMT), pname);
        va_start(alist, format);
        (void) vfprintf(stderr, format, alist);
        va_end(alist);
        if (strchr(format, '\n') == NULL)
                (void) fprintf(stderr, gettext(ERRNO_FMT), strerror(err));
}

/*PRINTFLIKE1*/
void
die(char *format, ...)
{
        int err = errno;
        va_list alist;

        if (pname != NULL)
                (void) fprintf(stderr, gettext(PNAME_FMT), pname);
        va_start(alist, format);
        (void) vfprintf(stderr, format, alist);
        va_end(alist);
        if (strchr(format, '\n') == NULL)
                (void) fprintf(stderr, gettext(ERRNO_FMT), strerror(err));

        /* close the libdladm handle if it was opened */
        if (dld_handle != NULL)
                dladm_close(dld_handle);

        exit(E_ERROR);
}

char *
setpname(char *arg0)
{
        char *p = strrchr(arg0, '/');

        if (p == NULL)
                p = arg0;
        else
                p++;
        pname = p;
        return (pname);
}

/*
 * Return the localized name of an accounting type.
 */
const char *
ac_type_name(int type)
{
        switch (type) {
        case AC_PROC:
                return (gettext("process"));
        case AC_FLOW:
                return (gettext("flow"));
        case AC_TASK:
                return (gettext("task"));
        case AC_NET:
                return (gettext("net"));
        default:
                die(gettext("invalid type %d\n"), type);
        }
        /* NOTREACHED */
        return (NULL);
}

/*
 * Open an accounting file.  The filename specified must be an absolute
 * pathname and the existing contents of the file (if any) must be of the
 * requested type.  Needs euid 0 to open the root-owned accounting file.
 * file_dac_write is required to create a new file in a directory not owned
 * by root (/var/adm/exacct is owned by 'adm').  Assumes sys_acct privilege is
 * already asserted by caller.
 */
int
open_exacct_file(const char *file, int type)
{
        int rc;
        int err;

        if (file[0] != '/') {
                warn(gettext("%s is not an absolute pathname\n"), file);
                return (-1);
        }
        if (!verify_exacct_file(file, type)) {
                warn(gettext("%s is not a %s accounting file\n"), file,
                    ac_type_name(type));
                return (-1);
        }
        if (seteuid(0) == -1 || setegid(0) == -1) {
                warn(gettext("seteuid()/setegid() failed"));
                return (-1);
        }
        assert(priv_ineffect(PRIV_SYS_ACCT));
        (void) priv_set(PRIV_ON, PRIV_EFFECTIVE, PRIV_FILE_DAC_WRITE, NULL);
        rc = acctctl(type | AC_FILE_SET, (void *) file, strlen(file) + 1);
        if (rc == -1 && (err = errno) == EBUSY) {
                char name[MAXPATHLEN];
                struct stat cur;
                struct stat new;

                /*
                 * The file is already open as an accounting file somewhere.
                 * If the file we're trying to open is the same as we have
                 * currently open then we're ok.
                 */
                if (acctctl(type | AC_FILE_GET, name, sizeof (name)) == 0 &&
                    stat(file, &new) != -1 && stat(name, &cur) != -1 &&
                    new.st_dev == cur.st_dev && new.st_ino == cur.st_ino)
                        rc = 0;
        }

        /*
         * euid 0, egid 0 and the file_dac_write privilege are no longer
         * required; give them up permanently.
         */
        (void) priv_set(PRIV_OFF, PRIV_PERMITTED, PRIV_FILE_DAC_WRITE, NULL);
        if (setreuid(getuid(), getuid()) == -1 ||
            setregid(getgid(), getgid()) == -1)
                die(gettext("setreuid()/setregid() failed"));
        if (rc == 0)
                return (0);

        warn(gettext("cannot open %s accounting file %s: %s\n"),
            ac_type_name(type), file, strerror(err));
        return (-1);
}

/*
 * Verify that the file contents (if any) are extended accounting records
 * of the desired type.
 */
boolean_t
verify_exacct_file(const char *file, int type)
{
        ea_file_t ef;
        ea_object_t eo;
        struct stat st;
        int err;

        if (stat(file, &st) != -1 && st.st_size != 0) {
                if (seteuid(0) == -1)
                        return (B_FALSE);
                err = ea_open(&ef, file, "SunOS", EO_TAIL, O_RDONLY, 0);
                if (seteuid(getuid()) == 1)
                        die(gettext("seteuid() failed"));
                if (err == -1)
                        return (B_FALSE);

                bzero(&eo, sizeof (eo));
                if (ea_previous_object(&ef, &eo) == EO_ERROR) {
                        /*
                         * EXR_EOF indicates there are no non-header objects
                         * in the file.  It can't be determined that this
                         * file is or is not the proper type of extended
                         * accounting file, which isn't necessarily an error.
                         * Since it is a proper (albeit empty) extended
                         * accounting file, it matches any desired type.
                         *
                         * if ea_previous_object() failed for any other reason
                         * than EXR_EOF, the file must be corrupt.
                         */
                        if (ea_error() != EXR_EOF) {
                                (void) ea_close(&ef);
                                return (B_FALSE);
                        }
                } else {
                        /*
                         * A non-header object exists.  Insist that it be
                         * either a process, task, flow  or net accounting
                         * record, the same type as is desired.
                         * xxx-venu:check 101 merge for EXD_GROUP_NET_*
                         */
                        uint_t c = eo.eo_catalog & EXD_DATA_MASK;

                        if (eo.eo_type != EO_GROUP ||
                            (eo.eo_catalog & EXC_CATALOG_MASK) != EXC_NONE ||
                            (!(c == EXD_GROUP_PROC && type == AC_PROC ||
                            c == EXD_GROUP_TASK && type == AC_TASK ||
                            c == EXD_GROUP_FLOW && type == AC_FLOW ||
                            (c == EXD_GROUP_NET_LINK_DESC ||
                            c == EXD_GROUP_NET_FLOW_DESC ||
                            c == EXD_GROUP_NET_LINK_STATS ||
                            c == EXD_GROUP_NET_FLOW_STATS) &&
                            type == AC_NET))) {
                                (void) ea_close(&ef);
                                return (B_FALSE);
                        }
                }
                (void) ea_close(&ef);
        }
        return (B_TRUE);
}