/*
 * Copyright (c) 1989, 1993, 1995
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
 * Portions 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.
 */

#include "port_before.h"

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

#include <errno.h>
#include <fcntl.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>

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

#include "port_after.h"

#include "irs_p.h"
#include "lcl_p.h"

#ifndef _PATH_PROTOCOLS
#define _PATH_PROTOCOLS "/etc/protocols"
#endif
#define MAXALIASES      35

/* Types */

struct pvt {
        FILE *          fp;
        char            line[BUFSIZ+1];
        char *          dbuf;
        struct protoent proto;
        char *          proto_aliases[MAXALIASES];
};

/* Forward */

static void                     pr_close(struct irs_pr *);
static struct protoent *        pr_next(struct irs_pr *);
static struct protoent *        pr_byname(struct irs_pr *, const char *);
static struct protoent *        pr_bynumber(struct irs_pr *, int);
static void                     pr_rewind(struct irs_pr *);
static void                     pr_minimize(struct irs_pr *);

/* Portability. */

#ifndef SEEK_SET
# define SEEK_SET 0
#endif

/* Public */

struct irs_pr *
irs_lcl_pr(struct irs_acc *this) {
        struct irs_pr *pr;
        struct pvt *pvt;

        if (!(pr = memget(sizeof *pr))) {
                errno = ENOMEM;
                return (NULL);
        }
        if (!(pvt = memget(sizeof *pvt))) {
                memput(pr, sizeof *this);
                errno = ENOMEM;
                return (NULL);
        }
        memset(pvt, 0, sizeof *pvt);
        pr->private = pvt;
        pr->close = pr_close;
        pr->byname = pr_byname;
        pr->bynumber = pr_bynumber;
        pr->next = pr_next;
        pr->rewind = pr_rewind;
        pr->minimize = pr_minimize;
        pr->res_get = NULL;
        pr->res_set = NULL;
        return (pr);
}

/* Methods */

static void
pr_close(struct irs_pr *this) {
        struct pvt *pvt = (struct pvt *)this->private;

        if (pvt->fp)
                (void) fclose(pvt->fp);
        if (pvt->dbuf)
                free(pvt->dbuf);
        memput(pvt, sizeof *pvt);
        memput(this, sizeof *this);
}

static struct protoent *
pr_byname(struct irs_pr *this, const char *name) {

        struct protoent *p;
        char **cp;

        pr_rewind(this);
        while ((p = pr_next(this))) {
                if (!strcmp(p->p_name, name))
                        goto found;
                for (cp = p->p_aliases; *cp; cp++)
                        if (!strcmp(*cp, name))
                                goto found;
        }
 found:
        return (p);
}

static struct protoent *
pr_bynumber(struct irs_pr *this, int proto) {
        struct protoent *p;

        pr_rewind(this);
        while ((p = pr_next(this)))
                if (p->p_proto == proto)
                        break;
        return (p);
}

static void
pr_rewind(struct irs_pr *this) {
        struct pvt *pvt = (struct pvt *)this->private;

        if (pvt->fp) {
                if (fseek(pvt->fp, 0L, SEEK_SET) == 0)
                        return;
                (void)fclose(pvt->fp);
        }
        if (!(pvt->fp = fopen(_PATH_PROTOCOLS, "r" )))
                return;
        if (fcntl(fileno(pvt->fp), F_SETFD, 1) < 0) {
                (void)fclose(pvt->fp);
                pvt->fp = NULL;
        }
}

static struct protoent *
pr_next(struct irs_pr *this) {
        struct pvt *pvt = (struct pvt *)this->private;
        char *p, *cp, **q;
        char *bufp, *ndbuf, *dbuf = NULL;
        int c, bufsiz, offset;

        if (!pvt->fp)
                pr_rewind(this);
        if (!pvt->fp)
                return (NULL);
        if (pvt->dbuf) {
                free(pvt->dbuf);
                pvt->dbuf = NULL;
        }
        bufp = pvt->line;
        bufsiz = BUFSIZ;
        offset = 0;
 again:
        if ((p = fgets(bufp + offset, bufsiz - offset, pvt->fp)) == NULL) {
                if (dbuf)
                        free(dbuf);
                return (NULL);
        }
        if (!strchr(p, '\n') && !feof(pvt->fp)) {
#define GROWBUF 1024
                /* allocate space for longer line */
                if (dbuf == NULL) {
                        if ((ndbuf = malloc(bufsiz + GROWBUF)) != NULL)
                                strcpy(ndbuf, bufp);
                } else
                        ndbuf = realloc(dbuf, bufsiz + GROWBUF);
                if (ndbuf) {
                        dbuf = ndbuf;
                        bufp = dbuf;
                        bufsiz += GROWBUF;
                        offset = strlen(dbuf);
                } else {
                        /* allocation failed; skip this long line */
                        while ((c = getc(pvt->fp)) != EOF)
                                if (c == '\n')
                                        break;
                        if (c != EOF)
                                ungetc(c, pvt->fp);
                }
                goto again;
        }

        p -= offset;
        offset = 0;

        if (*p == '#')
                goto again;
        cp = strpbrk(p, "#\n");
        if (cp != NULL)
                *cp = '\0';
        pvt->proto.p_name = p;
        cp = strpbrk(p, " \t");
        if (cp == NULL)
                goto again;
        *cp++ = '\0';
        while (*cp == ' ' || *cp == '\t')
                cp++;
        p = strpbrk(cp, " \t");
        if (p != NULL)
                *p++ = '\0';
        pvt->proto.p_proto = atoi(cp);
        q = pvt->proto.p_aliases = pvt->proto_aliases;
        if (p != NULL) {
                cp = p;
                while (cp && *cp) {
                        if (*cp == ' ' || *cp == '\t') {
                                cp++;
                                continue;
                        }
                        if (q < &pvt->proto_aliases[MAXALIASES - 1])
                                *q++ = cp;
                        cp = strpbrk(cp, " \t");
                        if (cp != NULL)
                                *cp++ = '\0';
                }
        }
        *q = NULL;
        pvt->dbuf = dbuf;
        return (&pvt->proto);
}

static void
pr_minimize(struct irs_pr *this) {
        struct pvt *pvt = (struct pvt *)this->private;

        if (pvt->fp != NULL) {
                (void)fclose(pvt->fp);
                pvt->fp = NULL;
        }
}

/*! \file */