common/irs/gen.c

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


/*
 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
 * Copyright (c) 1996-1999 by Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#if !defined(LINT) && !defined(CODECENTER)
static const char rcsid[] = "$Id: gen.c,v 1.7 2005/04/27 04:56:23 sra Exp $";
#endif

/*! \file
 * \brief
 * this is the top level dispatcher
 *
 * The dispatcher is implemented as an accessor class; it is an
 * accessor class that calls other accessor classes, as controlled by a
 * configuration file.
 *
 * A big difference between this accessor class and others is that the
 * map class initializers are NULL, and the map classes are already
 * filled in with method functions that will do the right thing.
 */

/* Imports */

#include "port_before.h"

#include <isc/assertions.h>
#include <ctype.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <resolv.h>

#include <isc/memcluster.h>
#include <irs.h>

#include "port_after.h"

#include "irs_p.h"
#include "gen_p.h"

#ifdef SUNW_HOSTS_FALLBACK
extern int __res_no_hosts_fallback(void);
#endif /* SUNW_HOSTS_FALLBACK */

/* Definitions */

struct nameval {
    const char *    name;
    int     val;
};

static const struct nameval acc_names[irs_nacc+1] = {
    { "local", irs_lcl },
    { "dns", irs_dns },
    { "nis", irs_nis },
    { "irp", irs_irp },
    { NULL, irs_nacc }
};

typedef struct irs_acc *(*accinit) __P((const char *options));

static const accinit accs[irs_nacc+1] = {
    irs_lcl_acc,
    irs_dns_acc,
#ifdef WANT_IRS_NIS
    irs_nis_acc,
#else
    NULL,
#endif
    irs_irp_acc,
    NULL
};

static const struct nameval map_names[irs_nmap+1] = {
    { "group", irs_gr },
    { "passwd", irs_pw },
    { "services", irs_sv },
    { "protocols", irs_pr },
    { "hosts", irs_ho },
    { "networks", irs_nw },
    { "netgroup", irs_ng },
    { NULL, irs_nmap }
};

static const struct nameval option_names[] = {
    { "merge", IRS_MERGE },
    { "continue", IRS_CONTINUE },
    { NULL, 0 }
};

/* Forward */

static void     gen_close(struct irs_acc *);
static struct __res_state * gen_res_get(struct irs_acc *);
static void     gen_res_set(struct irs_acc *, struct __res_state *,
                    void (*)(void *));
static int      find_name(const char *, const struct nameval nv[]);
static void         init_map_rules(struct gen_p *, const char *conf_file);
static struct irs_rule *release_rule(struct irs_rule *);
static int      add_rule(struct gen_p *,
                 enum irs_map_id, enum irs_acc_id,
                 const char *);

/* Public */

struct irs_acc *
irs_gen_acc(const char *options, const char *conf_file) {
    struct irs_acc *acc;
    struct gen_p *irs;

    if (!(acc = memget(sizeof *acc))) {
        errno = ENOMEM;
        return (NULL);
    }
    memset(acc, 0x5e, sizeof *acc);
    if (!(irs = memget(sizeof *irs))) {
        errno = ENOMEM;
        memput(acc, sizeof *acc);
        return (NULL);
    }
    memset(irs, 0x5e, sizeof *irs);
    irs->options = strdup(options);
    irs->res = NULL;
    irs->free_res = NULL;
    memset(irs->accessors, 0, sizeof irs->accessors);
    memset(irs->map_rules, 0, sizeof irs->map_rules);
    init_map_rules(irs, conf_file);
    acc->private = irs;
#ifdef WANT_IRS_GR
    acc->gr_map = irs_gen_gr;
#else
    acc->gr_map = NULL;
#endif
#ifdef WANT_IRS_PW
    acc->pw_map = irs_gen_pw;
#else
    acc->pw_map = NULL;
#endif
    acc->sv_map = irs_gen_sv;
    acc->pr_map = irs_gen_pr;
    acc->ho_map = irs_gen_ho;
    acc->nw_map = irs_gen_nw;
    acc->ng_map = irs_gen_ng;
    acc->res_get = gen_res_get;
    acc->res_set = gen_res_set;
    acc->close = gen_close;
    return (acc);
}

/* Methods */

static struct __res_state *
gen_res_get(struct irs_acc *this) {
    struct gen_p *irs = (struct gen_p *)this->private;

    if (irs->res == NULL) {
        struct __res_state *res;
        res = (struct __res_state *)malloc(sizeof *res);
        if (res == NULL)
            return (NULL);
        memset(res, 0, sizeof *res);
        gen_res_set(this, res, free);
    }

    if (((irs->res->options & RES_INIT) == 0U) && res_ninit(irs->res) < 0)
        return (NULL);

    return (irs->res);
}

static void
gen_res_set(struct irs_acc *this, struct __res_state *res,
        void (*free_res)(void *)) {
    struct gen_p *irs = (struct gen_p *)this->private;
#if 0
    struct irs_rule *rule;
    struct irs_ho *ho;
    struct irs_nw *nw;
#endif

    if (irs->res && irs->free_res) {
        res_nclose(irs->res);
        (*irs->free_res)(irs->res);
    }

    irs->res = res;
    irs->free_res = free_res;

#if 0
    for (rule = irs->map_rules[irs_ho]; rule; rule = rule->next) {
                ho = rule->inst->ho;

                (*ho->res_set)(ho, res, NULL);
    }
    for (rule = irs->map_rules[irs_nw]; rule; rule = rule->next) {
                nw = rule->inst->nw;

                (*nw->res_set)(nw, res, NULL);
    }
#endif
}

static void
gen_close(struct irs_acc *this) {
    struct gen_p *irs = (struct gen_p *)this->private;
    int n;

    /* Search rules. */
    for (n = 0; n < irs_nmap; n++)
        while (irs->map_rules[n] != NULL)
            irs->map_rules[n] = release_rule(irs->map_rules[n]);

    /* Access methods. */
    for (n = 0; n < irs_nacc; n++) {
        /* Map objects. */
        if (irs->accessors[n].gr != NULL)
            (*irs->accessors[n].gr->close)(irs->accessors[n].gr);
        if (irs->accessors[n].pw != NULL)
            (*irs->accessors[n].pw->close)(irs->accessors[n].pw);
        if (irs->accessors[n].sv != NULL)
            (*irs->accessors[n].sv->close)(irs->accessors[n].sv);
        if (irs->accessors[n].pr != NULL)
            (*irs->accessors[n].pr->close)(irs->accessors[n].pr);
        if (irs->accessors[n].ho != NULL)
            (*irs->accessors[n].ho->close)(irs->accessors[n].ho);
        if (irs->accessors[n].nw != NULL)
            (*irs->accessors[n].nw->close)(irs->accessors[n].nw);
        if (irs->accessors[n].ng != NULL)
            (*irs->accessors[n].ng->close)(irs->accessors[n].ng);
        /* Enclosing accessor. */
        if (irs->accessors[n].acc != NULL)
            (*irs->accessors[n].acc->close)(irs->accessors[n].acc);
    }

    /* The options string was strdup'd. */
    free((void*)irs->options);

    if (irs->res && irs->free_res)
        (*irs->free_res)(irs->res);

    /* The private data container. */
    memput(irs, sizeof *irs);

    /* The object. */
    memput(this, sizeof *this);
}

/* Private */

static int
find_name(const char *name, const struct nameval names[]) {
    int n;

    for (n = 0; names[n].name != NULL; n++)
        if (strcmp(name, names[n].name) == 0)
            return (names[n].val);
    return (-1);
}

static struct irs_rule *
release_rule(struct irs_rule *rule) {
    struct irs_rule *next = rule->next;

    memput(rule, sizeof *rule);
    return (next);
}

static int
add_rule(struct gen_p *irs,
     enum irs_map_id map, enum irs_acc_id acc,
     const char *options)
{
    struct irs_rule **rules, *last, *tmp, *new;
    struct irs_inst *inst;
    const char *cp;
    int n;

#ifndef WANT_IRS_GR
    if (map == irs_gr)
        return (-1);
#endif
#ifndef WANT_IRS_PW
    if (map == irs_pw)
        return (-1);
#endif
#ifndef WANT_IRS_NIS
    if (acc == irs_nis)
        return (-1);
#endif
    new = memget(sizeof *new);
    if (new == NULL)
        return (-1);
    memset(new, 0x5e, sizeof *new);
    new->next = NULL;

    new->inst = &irs->accessors[acc];

    new->flags = 0;
    cp = options;
    while (cp && *cp) {
        char option[50], *next;

        next = strchr(cp, ',');
        if (next)
            n = next++ - cp;
        else
            n = strlen(cp);
        if ((size_t)n > sizeof option - 1)
            n = sizeof option - 1;
        strncpy(option, cp, n);
        option[n] = '\0';

        n = find_name(option, option_names);
        if (n >= 0)
            new->flags |= n;

        cp = next;
    }

    rules = &irs->map_rules[map];
    for (last = NULL, tmp = *rules;
         tmp != NULL;
         last = tmp, tmp = tmp->next)
        (void)NULL;
    if (last == NULL)
        *rules = new;
    else
        last->next = new;

    /* Try to instantiate map accessors for this if necessary & approp. */
    inst = &irs->accessors[acc];
    if (inst->acc == NULL && accs[acc] != NULL)
        inst->acc = (*accs[acc])(irs->options);
    if (inst->acc != NULL) {
        if (inst->gr == NULL && inst->acc->gr_map != NULL)
            inst->gr = (*inst->acc->gr_map)(inst->acc);
        if (inst->pw == NULL && inst->acc->pw_map != NULL)
            inst->pw = (*inst->acc->pw_map)(inst->acc);
        if (inst->sv == NULL && inst->acc->sv_map != NULL)
            inst->sv = (*inst->acc->sv_map)(inst->acc);
        if (inst->pr == NULL && inst->acc->pr_map != NULL)
            inst->pr = (*inst->acc->pr_map)(inst->acc);
        if (inst->ho == NULL && inst->acc->ho_map != NULL)
            inst->ho = (*inst->acc->ho_map)(inst->acc);
        if (inst->nw == NULL && inst->acc->nw_map != NULL)
            inst->nw = (*inst->acc->nw_map)(inst->acc);
        if (inst->ng == NULL && inst->acc->ng_map != NULL)
            inst->ng = (*inst->acc->ng_map)(inst->acc);
    }

    return (0);
}

static void
default_map_rules(struct gen_p *irs) {
    /* Install time honoured and proved BSD style rules as default. */
    add_rule(irs, irs_gr, irs_lcl, "");
    add_rule(irs, irs_pw, irs_lcl, "");
    add_rule(irs, irs_sv, irs_lcl, "");
    add_rule(irs, irs_pr, irs_lcl, "");
#ifdef SUNW_HOSTS_FALLBACK
    if (__res_no_hosts_fallback())
        add_rule(irs, irs_ho, irs_dns, "");
    else {
        add_rule(irs, irs_ho, irs_dns, "continue");
        add_rule(irs, irs_ho, irs_lcl, "");
    }
#else  /* SUNW_HOSTS_FALLBACK */
    add_rule(irs, irs_ho, irs_dns, "continue");
    add_rule(irs, irs_ho, irs_lcl, "");
#endif /* SUNW_HOSTS_FALLBACK */
    add_rule(irs, irs_nw, irs_dns, "continue");
    add_rule(irs, irs_nw, irs_lcl, "");
    add_rule(irs, irs_ng, irs_lcl, "");
}

static void
init_map_rules(struct gen_p *irs, const char *conf_file) {
    char line[1024], pattern[40], mapname[20], accname[20], options[100];
    FILE *conf;

#ifdef SUNW_HOSTS_FALLBACK
    if (__res_no_hosts_fallback()) {
        default_map_rules(irs);
        return;
    }
#endif /* SUNW_HOSTS_FALLBACK */

    if (conf_file == NULL)
        conf_file = _PATH_IRS_CONF ;

    /* A conf file of "" means compiled in defaults. Irpd wants this */
    if (conf_file[0] == '\0' || (conf = fopen(conf_file, "r")) == NULL) {
        default_map_rules(irs);
        return;
    }
    (void) sprintf(pattern, "%%%lus %%%lus %%%lus\n",
               (unsigned long)sizeof mapname,
               (unsigned long)sizeof accname,
               (unsigned long)sizeof options);
    while (fgets(line, sizeof line, conf)) {
        enum irs_map_id map;
        enum irs_acc_id acc;
        char *tmp;
        int n;

        for (tmp = line;
             isascii((unsigned char)*tmp) &&
             isspace((unsigned char)*tmp);
             tmp++)
            (void)NULL;
        if (*tmp == '#' || *tmp == '\n' || *tmp == '\0')
            continue;
        n = sscanf(tmp, pattern, mapname, accname, options);
        if (n < 2)
            continue;
        if (n < 3)
            options[0] = '\0';

        n = find_name(mapname, map_names);
        INSIST(n < irs_nmap);
        if (n < 0)
            continue;
        map = (enum irs_map_id) n;

        n = find_name(accname, acc_names);
        INSIST(n < irs_nacc);
        if (n < 0)
            continue;
        acc = (enum irs_acc_id) n;

        add_rule(irs, map, acc, options);
    }
    fclose(conf);
}