/*      $OpenBSD: getservent.c,v 1.16 2026/03/10 00:06:39 deraadt Exp $ */
/*
 * Copyright (c) 1983, 1993
 *      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. 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.
 */

#include <sys/types.h>
#include <sys/socket.h>

#include <errno.h>
#include <limits.h>
#include <netdb.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>

void
setservent_r(int f, struct servent_data *sd)
{
        if (sd->fp == NULL) {
                int fd = __pledge_open(_PATH_SERVICES, O_RDONLY|O_CLOEXEC);
                if (fd != -1)
                        sd->fp = fdopen(fd, "r" );
                if (sd->fp == NULL)
                        close(fd);
        } else
                rewind(sd->fp);
        sd->stayopen |= f;
}
DEF_WEAK(setservent_r);

void
endservent_r(struct servent_data *sd)
{
        if (sd->fp) {
                fclose(sd->fp);
                sd->fp = NULL;
        }
        free(sd->aliases);
        sd->aliases = NULL;
        sd->maxaliases = 0;
        free(sd->line);
        sd->line = NULL;
        sd->stayopen = 0;
}
DEF_WEAK(endservent_r);

int
getservent_r(struct servent *se, struct servent_data *sd)
{
        char *p, *cp, **q, *endp;
        size_t len;
        long l;
        int serrno;

        if (sd->fp == NULL) {
                int fd = __pledge_open(_PATH_SERVICES, O_RDONLY|O_CLOEXEC);
                if (fd == -1)
                        return (-1);
                if ((sd->fp = fdopen(fd, "r" )) == NULL) {
                        close(fd);
                        return (-1);
                }
        }
again:
        if ((p = fgetln(sd->fp, &len)) == NULL)
                return (-1);
        if (len == 0 || *p == '#' || *p == '\n')
                goto again;
        if (p[len-1] == '\n')
                len--;
        if ((cp = memchr(p, '#', len)) != NULL)
                len = cp - p;
        cp = realloc(sd->line, len + 1);
        if (cp == NULL)
                return (-1);
        sd->line = se->s_name = memcpy(cp, p, len);
        cp[len] = '\0';
        p = strpbrk(cp, " \t");
        if (p == NULL)
                goto again;
        *p++ = '\0';
        while (*p == ' ' || *p == '\t')
                p++;
        cp = strpbrk(p, ",/");
        if (cp == NULL)
                goto again;
        *cp++ = '\0';
        l = strtol(p, &endp, 10);
        if (endp == p || *endp != '\0' || l < 0 || l > USHRT_MAX)
                goto again;
        se->s_port = htons((in_port_t)l);
        se->s_proto = cp;
        if (sd->aliases == NULL) {
                sd->maxaliases = 10;
                sd->aliases = calloc(sd->maxaliases, sizeof(char *));
                if (sd->aliases == NULL) {
                        serrno = errno;
                        endservent_r(sd);
                        errno = serrno;
                        return (-1);
                }
        }
        q = se->s_aliases = sd->aliases;
        cp = strpbrk(cp, " \t");
        if (cp != NULL)
                *cp++ = '\0';
        while (cp && *cp) {
                if (*cp == ' ' || *cp == '\t') {
                        cp++;
                        continue;
                }
                if (q == &se->s_aliases[sd->maxaliases - 1]) {
                        p = reallocarray(se->s_aliases, sd->maxaliases,
                            2 * sizeof(char *));
                        if (p == NULL) {
                                serrno = errno;
                                endservent_r(sd);
                                errno = serrno;
                                return (-1);
                        }
                        sd->maxaliases *= 2;
                        q = (char **)p + (q - se->s_aliases);
                        se->s_aliases = sd->aliases = (char **)p;
                }
                *q++ = cp;
                cp = strpbrk(cp, " \t");
                if (cp != NULL)
                        *cp++ = '\0';
        }
        *q = NULL;
        return (0);
}
DEF_WEAK(getservent_r);

struct servent_data _servent_data;      /* shared with getservby{name,port}.c */

void
setservent(int f)
{
        setservent_r(f, &_servent_data);
}

void
endservent(void)
{
        endservent_r(&_servent_data);
}

struct servent *
getservent(void)
{
        static struct servent serv;

        if (getservent_r(&serv, &_servent_data) != 0)
                return (NULL);
        return (&serv);
}