libfmd_snmp/common/scheme.c

	scheme.c revision 1fe76c0bac8011fcb2a7d8a4a83b76700787dd5c
/*
 * 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 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

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

#include <sys/fm/protocol.h>
#include <sys/types.h>
#include <sys/systeminfo.h>
#include <fm/fmd_snmp.h>
#include <fm/libtopo.h>
#include <net-snmp/net-snmp-config.h>
#include <net-snmp/net-snmp-includes.h>
#include <net-snmp/agent/net-snmp-agent-includes.h>
#include <libnvpair.h>
#include <limits.h>
#include <strings.h>
#include <stddef.h>
#include <unistd.h>
#include <dlfcn.h>
#include <errno.h>

#define SCHEMEDIR_BASE  "/usr/lib/fm/fmd/schemes"

#if defined(__sparcv9)
#define DEFAULTSCHEMEDIR    SCHEMEDIR_BASE "/sparcv9"
#elif defined(__amd64)
#define DEFAULTSCHEMEDIR    SCHEMEDIR_BASE "/amd64"
#else
#define DEFAULTSCHEMEDIR    SCHEMEDIR_BASE
#endif

typedef struct fmd_scheme_ops {
    int (*sop_init)(void);
    void (*sop_fini)(void);
    ssize_t (*sop_nvl2str)(nvlist_t *, char *, size_t);
} fmd_scheme_ops_t;

typedef struct fmd_scheme_opd {
    const char *opd_name;       /* symbol name of scheme function */
    size_t opd_off;         /* offset within fmd_scheme_ops_t */
} fmd_scheme_opd_t;

typedef struct fmd_scheme {
    struct fmd_scheme *sch_next;    /* next scheme on list of schemes */
    char *sch_name;         /* name of this scheme (fmri prefix) */
    void *sch_dlp;          /* libdl(3DL) shared library handle */
    int sch_err;            /* if negative entry, errno to return */
    fmd_scheme_ops_t sch_ops;   /* scheme function pointers */
} fmd_scheme_t;

static fmd_scheme_t *sch_list;      /* list of cached schemes */
static char *g_root;            /* fmd root dir */
static struct topo_hdl *g_thp;

static long
fmd_scheme_notsup(void)
{
    errno = ENOTSUP;
    return (-1);
}

static int
fmd_scheme_nop(void)
{
    return (0);
}

/*
 * Default values for the scheme ops.  If a scheme function is not defined in
 * the module, then this operation is implemented using the default function.
 */
static const fmd_scheme_ops_t _fmd_scheme_default_ops = {
    (int (*)())fmd_scheme_nop,      /* sop_init */
    (void (*)())fmd_scheme_nop,     /* sop_fini */
    (ssize_t (*)())fmd_scheme_notsup,   /* sop_nvl2str */
};

/*
 * Scheme ops descriptions.  These names and offsets are used by the function
 * fmd_scheme_rtld_init(), defined below, to load up a fmd_scheme_ops_t.
 */
static const fmd_scheme_opd_t _fmd_scheme_ops[] = {
    { "fmd_fmri_init", offsetof(fmd_scheme_ops_t, sop_init) },
    { "fmd_fmri_fini", offsetof(fmd_scheme_ops_t, sop_fini) },
    { "fmd_fmri_nvl2str", offsetof(fmd_scheme_ops_t, sop_nvl2str) },
    { NULL, 0 }
};

static fmd_scheme_t *
fmd_scheme_create(const char *name)
{
    fmd_scheme_t *sp;

    if ((sp = malloc(sizeof (fmd_scheme_t))) == NULL ||
        (sp->sch_name = strdup(name)) == NULL) {
        free(sp);
        return (NULL);
    }

    sp->sch_next = sch_list;
    sp->sch_dlp = NULL;
    sp->sch_err = 0;
    sp->sch_ops = _fmd_scheme_default_ops;

    sch_list = sp;
    return (sp);
}

static int
fmd_scheme_rtld_init(fmd_scheme_t *sp)
{
    const fmd_scheme_opd_t *opd;
    void *p;

    for (opd = _fmd_scheme_ops; opd->opd_name != NULL; opd++) {
        if ((p = dlsym(sp->sch_dlp, opd->opd_name)) != NULL)
            *(void **)((uintptr_t)&sp->sch_ops + opd->opd_off) = p;
    }

    return (sp->sch_ops.sop_init());
}

static fmd_scheme_t *
fmd_scheme_lookup(const char *dir, const char *name)
{
    fmd_scheme_t *sp;
    char path[PATH_MAX];

    for (sp = sch_list; sp != NULL; sp = sp->sch_next) {
        if (strcmp(name, sp->sch_name) == 0)
            return (sp);
    }

    if ((sp = fmd_scheme_create(name)) == NULL)
        return (NULL); /* errno is set for us */

    (void) snprintf(path, sizeof (path), "%s%s/%s.so",
        g_root ? g_root : "", dir, name);

    if (access(path, F_OK) != 0) {
        sp->sch_err = errno;
        return (sp);
    }

    if ((sp->sch_dlp = dlopen(path, RTLD_LOCAL | RTLD_NOW | RTLD_PARENT)) ==
        NULL) {
        sp->sch_err = ELIBACC;
        return (sp);
    }

    if (fmd_scheme_rtld_init(sp) != 0) {
        sp->sch_err = errno;
        (void) dlclose(sp->sch_dlp);
        sp->sch_dlp = NULL;
    }

    return (sp);
}

char *
sunFm_nvl2str(nvlist_t *nvl)
{
    fmd_scheme_t *sp;
    char c, *name, *s = NULL;
    ssize_t len;

    if (nvlist_lookup_string(nvl, FM_FMRI_SCHEME, &name) != 0) {
        DEBUGMSGTL((MODNAME_STR, "fmri does not contain required "
            "'%s' nvpair\n", FM_FMRI_SCHEME));
        return (NULL);
    }

    if ((sp = fmd_scheme_lookup(DEFAULTSCHEMEDIR, name)) == NULL ||
        sp->sch_dlp == NULL || sp->sch_err != 0) {
        const char *msg =
            sp->sch_err == ELIBACC ? dlerror() : strerror(sp->sch_err);
        DEBUGMSGTL((MODNAME_STR, "cannot init '%s' scheme library to "
            "format fmri: %s\n", name, msg ? msg : "unknown error"));
        return (NULL);
    }

    if ((len = sp->sch_ops.sop_nvl2str(nvl, &c, sizeof (c))) == -1 ||
        (s = malloc(len + 1)) == NULL ||
        sp->sch_ops.sop_nvl2str(nvl, s, len + 1) == -1) {
        DEBUGMSGTL((MODNAME_STR, "cannot format fmri using scheme '%s'",
            name));
        free(s);
        return (NULL);
    }

    return (s);
}

void *
fmd_fmri_alloc(size_t size)
{
    return (malloc(size));
}

void *
fmd_fmri_zalloc(size_t size)
{
    void *data;

    if ((data = malloc(size)) != NULL)
        bzero(data, size);

    return (data);
}

/*ARGSUSED*/
void
fmd_fmri_free(void *data, size_t size)
{
    free(data);
}

int
fmd_fmri_error(int err)
{
    errno = err;
    return (-1);
}

char *
fmd_fmri_strescape(const char *s)
{
    return (strdup(s));
}

char *
fmd_fmri_strdup(const char *s)
{
    return (strdup(s));
}

void
fmd_fmri_strfree(char *s)
{
    free(s);
}

const char *
fmd_fmri_get_rootdir(void)
{
    return (g_root ? g_root : "");
}

const char *
fmd_fmri_get_platform(void)
{
    static char platform[MAXNAMELEN];

    if (platform[0] == '\0')
        (void) sysinfo(SI_PLATFORM, platform, sizeof (platform));

    return (platform);
}

uint64_t
fmd_fmri_get_drgen(void)
{
    return (0);
}

int
fmd_fmri_set_errno(int err)
{
    errno = err;
    return (-1);
}

/*ARGSUSED*/
void
fmd_fmri_warn(const char *format, ...)
{
}

/*ARGSUSED*/
struct topo_hdl *
fmd_fmri_topology(int version)
{
    int err;

    if (g_thp == NULL) {
        if ((g_thp = topo_open(TOPO_VERSION, "/", &err)) == NULL) {
            DEBUGMSGTL((MODNAME_STR, "topo_open failed: %s\n",
                topo_strerror(err)));
            return (NULL);
        }
    }

    return (g_thp);
}