971 lines
27 KiB
C
971 lines
27 KiB
C
/* ifchd.c - interface change daemon
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* Time-stamp: <2011-05-30 10:30:20 njk>
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*
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* (C) 2004-2011 Nicholas J. Kain <njkain at gmail dot com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <unistd.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/socket.h>
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#include <sys/un.h>
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#include <sys/time.h>
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#include <sys/types.h>
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#include <sys/epoll.h>
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#include <sys/signalfd.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <time.h>
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#include <pwd.h>
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#include <grp.h>
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#include <signal.h>
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#include <errno.h>
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#define _GNU_SOURCE
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#include <getopt.h>
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#include "ifchd-defines.h"
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#include "malloc.h"
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#include "log.h"
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#include "chroot.h"
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#include "pidfile.h"
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#include "signals.h"
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#include "strlist.h"
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#include "ifproto.h"
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#include "strl.h"
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#include "cap.h"
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#include "io.h"
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#include "linux.h"
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enum states {
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STATE_NOTHING,
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STATE_INTERFACE,
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STATE_IP,
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STATE_SUBNET,
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STATE_TIMEZONE,
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STATE_ROUTER,
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STATE_TIMESVR,
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STATE_DNS,
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STATE_LPRSVR,
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STATE_HOSTNAME,
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STATE_DOMAIN,
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STATE_IPTTL,
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STATE_MTU,
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STATE_BROADCAST,
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STATE_NTPSRV,
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STATE_WINS
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};
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static int epollfd, signalFd;
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/* Extra two event slots are for signalFd and the listen socket. */
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static struct epoll_event events[SOCK_QUEUE+2];
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/* Socket fd, current state, and idle time for connections. */
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static int sks[SOCK_QUEUE], state[SOCK_QUEUE], idle_time[SOCK_QUEUE];
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/* Per-connection buffers. */
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static char ibuf[SOCK_QUEUE][MAX_BUF];
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/*
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* Per-connection pointers into the command lists. Respectively, the
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* topmost item on the list, the current item, and the last item on the list.
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*/
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static strlist_t *head[SOCK_QUEUE], *curl[SOCK_QUEUE], *last[SOCK_QUEUE];
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int resolv_conf_fd = -1;
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/* int ntp_conf_fd = -1; */
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/* If true, allow HOSTNAME changes from dhcp server. */
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int allow_hostname = 0;
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static uid_t peer_uid;
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static gid_t peer_gid;
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static pid_t peer_pid;
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static int gflags_verbose = 0;
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/* Lists of nameservers and search domains. Unfortunately they must be
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* per-connection, since otherwise seperate clients could race against
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* one another to write out unpredictable data.
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*/
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static strlist_t *namesvrs[SOCK_QUEUE];
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static strlist_t *domains[SOCK_QUEUE];
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static void die_nulstr(strlist_t *p)
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{
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if (!p)
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suicide("FATAL - NULL passed to die_nulstr");
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if (!p->str)
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suicide("FATAL - NULL string in strlist");
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}
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static void writeordie(int fd, const char *buf, int len)
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{
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if (safe_write(fd, buf, len) == -1)
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suicide("write returned error");
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}
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static void epoll_add(int fd)
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{
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struct epoll_event ev;
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int r;
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ev.events = EPOLLIN | EPOLLRDHUP | EPOLLERR | EPOLLHUP;
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ev.data.fd = fd;
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r = epoll_ctl(epollfd, EPOLL_CTL_ADD, fd, &ev);
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if (r == -1)
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suicide("epoll_add failed %s", strerror(errno));
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}
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static void epoll_del(int fd)
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{
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struct epoll_event ev;
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int r;
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ev.events = EPOLLIN | EPOLLRDHUP | EPOLLERR | EPOLLHUP;
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ev.data.fd = fd;
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r = epoll_ctl(epollfd, EPOLL_CTL_DEL, fd, &ev);
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if (r == -1)
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suicide("epoll_del failed %s", strerror(errno));
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}
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/* Abstracts away the details of accept()ing a socket connection. */
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/* Writes out each element in a strlist as an argument to a keyword in
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* a file. */
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static void write_resolve_list(const char *keyword, strlist_t *list)
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{
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char *buf;
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strlist_t *p = list;
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unsigned int len;
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if (!keyword || resolv_conf_fd == -1)
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return;
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while (p) {
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buf = p->str;
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len = strlen(buf);
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if (len) {
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writeordie(resolv_conf_fd, keyword, strlen(keyword));
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writeordie(resolv_conf_fd, buf, strlen(buf));
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writeordie(resolv_conf_fd, "\n", 1);
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}
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p = p->next;
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}
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}
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/* Writes a new resolv.conf based on the information we have received. */
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static void write_resolve_conf(int idx)
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{
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int r;
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off_t off;
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if (resolv_conf_fd == -1)
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return;
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if (lseek(resolv_conf_fd, 0, SEEK_SET) == -1)
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return;
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write_resolve_list("nameserver ", namesvrs[idx]);
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write_resolve_list("search ", domains[idx]);
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off = lseek(resolv_conf_fd, 0, SEEK_CUR);
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if (off == -1) {
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log_line("write_resolve_conf: lseek returned error: %s\n",
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strerror(errno));
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return;
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}
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retry:
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r = ftruncate(resolv_conf_fd, off);
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if (r == -1) {
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if (errno == EINTR)
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goto retry;
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log_line("write_resolve_conf: ftruncate returned error: %s\n",
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strerror(errno));
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return;
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}
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r = fsync(resolv_conf_fd);
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if (r == -1) {
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log_line("write_resolve_conf: fsync returned error: %s\n",
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strerror(errno));
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return;
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}
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}
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/* Decomposes a ' '-delimited flat character array onto a strlist, then
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* calls the given function to perform work on the generated strlist. */
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static void parse_list(int idx, char *str, strlist_t **toplist,
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void (*fn)(int))
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{
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char *p, n[256];
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unsigned int i;
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strlist_t *newn = 0;
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if (!str || !toplist || !fn)
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return;
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p = str;
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while (p != '\0') {
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memset(n, '\0', sizeof n);
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for (i = 0; i < sizeof n - 1 && *p != '\0' && *p != ' '; ++p, ++i)
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n[i] = *p;
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if (*p == ' ')
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++p;
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add_to_strlist(&newn, n);
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}
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if (newn) {
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free_strlist(*toplist);
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*toplist = newn;
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} else
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return;
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(*fn)(idx);
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}
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/* XXX: addme */
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static void perform_timezone(int idx, char *str)
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{}
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/* Does anyone use this command? */
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static void perform_timesvr(int idx, char *str)
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{}
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/* Add a dns server to the /etc/resolv.conf -- we already have a fd. */
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static void perform_dns(int idx, char *str)
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{
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if (!str || resolv_conf_fd == -1)
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return;
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parse_list(idx, str, &(namesvrs[idx]), &write_resolve_conf);
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}
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/* Updates for print daemons are too non-standard to be useful. */
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static void perform_lprsvr(int idx, char *str)
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{}
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/* Sets machine hostname. */
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static void perform_hostname(int idx, char *str)
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{
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if (!allow_hostname || !str)
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return;
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if (sethostname(str, strlen(str) + 1) == -1)
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log_line("sethostname returned %s\n", strerror(errno));
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}
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/* update "search" in /etc/resolv.conf */
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static void perform_domain(int idx, char *str)
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{
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if (!str || resolv_conf_fd == -1)
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return;
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parse_list(idx, str, &(domains[idx]), &write_resolve_conf);
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}
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/* I don't think this can be done without a netfilter extension
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* that isn't in the mainline kernels. */
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static void perform_ipttl(int idx, char *str)
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{}
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/* XXX: addme */
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static void perform_ntpsrv(int idx, char *str)
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{}
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/* Maybe Samba cares about this feature? I don't know. */
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static void perform_wins(int idx, char *str)
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{}
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/* Wipes all state associated with a given connection. */
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static void new_sk(int idx, int val)
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{
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sks[idx] = val;
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memset(ibuf[idx], '\0', sizeof(ibuf[idx]));
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free_strlist(head[idx]);
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free_strlist(namesvrs[idx]);
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free_strlist(domains[idx]);
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head[idx] = NULL;
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curl[idx] = NULL;
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last[idx] = NULL;
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namesvrs[idx] = NULL;
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domains[idx] = NULL;
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idle_time[idx] = time(NULL);
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state[idx] = STATE_NOTHING;
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clear_if_data(idx);
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}
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/* Conditionally accepts a new connection and initializes data structures. */
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static void add_sk(int sk)
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{
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int i;
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if (authorized_peer(sk, peer_pid, peer_uid, peer_gid)) {
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for (i = 0; i < SOCK_QUEUE; i++)
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if (sks[i] == -1) {
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new_sk(i, sk);
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epoll_add(sk);
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return;
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}
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}
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close(sk);
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}
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/* Closes idle connections. */
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static void close_idle_sk(void)
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{
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int i;
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for (i=0; i<SOCK_QUEUE; i++) {
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if (sks[i] == -1)
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continue;
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if (time(NULL) - idle_time[i] > CONN_TIMEOUT) {
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epoll_del(sks[i]);
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close(sks[i]);
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new_sk(i, -1);
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}
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}
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}
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/* Decomposes a ':'-delimited flat character array onto a strlist. */
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static int stream_onto_list(int i)
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{
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int e, s;
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for (e = 0, s = 0; ibuf[i][e] != '\0'; e++) {
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if (ibuf[i][e] == ':') {
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/* Zero-length command: skip. */
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if (s == e) {
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s = e + 1;
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continue;
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}
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curl[i] = xmalloc(sizeof(strlist_t));
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if (head[i] == NULL) {
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head[i] = curl[i];
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last[i] = NULL;
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}
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curl[i]->next = NULL;
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if (last[i] != NULL)
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last[i]->next = curl[i];
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curl[i]->str = xmalloc(e - s + 1);
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strlcpy(curl[i]->str, ibuf[i] + s, e - s + 1);
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last[i] = curl[i];
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s = e + 1;
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}
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}
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return s;
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}
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/* State machine that runs over the command and argument list,
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* executing commands. */
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static void execute_list(int i)
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{
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char *p;
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for (;;) {
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if (!curl[i])
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break;
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die_nulstr(curl[i]);
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p = curl[i]->str;
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if (gflags_verbose)
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log_line("execute_list - p = '%s'", p);
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switch (state[i]) {
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case STATE_NOTHING:
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if (strncmp(p, CMD_INTERFACE, sizeof(CMD_INTERFACE)) == 0)
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state[i] = STATE_INTERFACE;
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if (strncmp(p, CMD_IP, sizeof(CMD_IP)) == 0)
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state[i] = STATE_IP;
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if (strncmp(p, CMD_SUBNET, sizeof(CMD_SUBNET)) == 0)
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state[i] = STATE_SUBNET;
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if (strncmp(p, CMD_TIMEZONE, sizeof(CMD_TIMEZONE)) == 0)
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state[i] = STATE_TIMEZONE;
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if (strncmp(p, CMD_ROUTER, sizeof(CMD_ROUTER)) == 0)
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state[i] = STATE_ROUTER;
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if (strncmp(p, CMD_TIMESVR, sizeof(CMD_TIMESVR)) == 0)
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state[i] = STATE_TIMESVR;
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if (strncmp(p, CMD_DNS, sizeof(CMD_DNS)) == 0)
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state[i] = STATE_DNS;
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if (strncmp(p, CMD_LPRSVR, sizeof(CMD_LPRSVR)) == 0)
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state[i] = STATE_LPRSVR;
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if (strncmp(p, CMD_HOSTNAME, sizeof(CMD_HOSTNAME)) == 0)
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state[i] = STATE_HOSTNAME;
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if (strncmp(p, CMD_DOMAIN, sizeof(CMD_DOMAIN)) == 0)
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state[i] = STATE_DOMAIN;
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if (strncmp(p, CMD_IPTTL, sizeof(CMD_IPTTL)) == 0)
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state[i] = STATE_IPTTL;
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if (strncmp(p, CMD_MTU, sizeof(CMD_MTU)) == 0)
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state[i] = STATE_MTU;
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if (strncmp(p, CMD_BROADCAST, sizeof(CMD_BROADCAST)) == 0)
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state[i] = STATE_BROADCAST;
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if (strncmp(p, CMD_NTPSRV, sizeof(CMD_NTPSRV)) == 0)
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state[i] = STATE_NTPSRV;
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if (strncmp(p, CMD_WINS, sizeof(CMD_WINS)) == 0)
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state[i] = STATE_WINS;
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free_stritem(&(curl[i]));
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break;
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case STATE_INTERFACE:
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perform_interface(i, p);
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free_stritem(&(curl[i]));
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state[i] = STATE_NOTHING;
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break;
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case STATE_IP:
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perform_ip(i, p);
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free_stritem(&(curl[i]));
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state[i] = STATE_NOTHING;
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break;
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case STATE_SUBNET:
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perform_subnet(i, p);
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free_stritem(&(curl[i]));
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state[i] = STATE_NOTHING;
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break;
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case STATE_TIMEZONE:
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perform_timezone(i, p);
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free_stritem(&(curl[i]));
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state[i] = STATE_NOTHING;
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break;
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case STATE_ROUTER:
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perform_router(i, p);
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free_stritem(&(curl[i]));
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state[i] = STATE_NOTHING;
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break;
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case STATE_TIMESVR:
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perform_timesvr(i, p);
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free_stritem(&(curl[i]));
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state[i] = STATE_NOTHING;
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break;
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|
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case STATE_DNS:
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perform_dns(i, p);
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free_stritem(&(curl[i]));
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state[i] = STATE_NOTHING;
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break;
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|
|
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case STATE_LPRSVR:
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perform_lprsvr(i, p);
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free_stritem(&(curl[i]));
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state[i] = STATE_NOTHING;
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break;
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|
|
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case STATE_HOSTNAME:
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perform_hostname(i, p);
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free_stritem(&(curl[i]));
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state[i] = STATE_NOTHING;
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break;
|
|
|
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case STATE_DOMAIN:
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perform_domain(i, p);
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free_stritem(&(curl[i]));
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state[i] = STATE_NOTHING;
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break;
|
|
|
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case STATE_IPTTL:
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perform_ipttl(i, p);
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free_stritem(&(curl[i]));
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state[i] = STATE_NOTHING;
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break;
|
|
|
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case STATE_MTU:
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perform_mtu(i, p);
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free_stritem(&(curl[i]));
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state[i] = STATE_NOTHING;
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break;
|
|
|
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case STATE_BROADCAST:
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perform_broadcast(i, p);
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free_stritem(&(curl[i]));
|
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state[i] = STATE_NOTHING;
|
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break;
|
|
|
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case STATE_NTPSRV:
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perform_ntpsrv(i, p);
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free_stritem(&(curl[i]));
|
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state[i] = STATE_NOTHING;
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break;
|
|
|
|
case STATE_WINS:
|
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perform_wins(i, p);
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free_stritem(&(curl[i]));
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state[i] = STATE_NOTHING;
|
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break;
|
|
|
|
default:
|
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log_line("warning: invalid state in dispatch_work\n");
|
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break;
|
|
}
|
|
}
|
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head[i] = curl[i];
|
|
}
|
|
|
|
/* Opens a non-blocking listening socket with the appropriate properties. */
|
|
static int get_listen(void)
|
|
{
|
|
int lsock, ret;
|
|
struct sockaddr_un lsock_addr =
|
|
{
|
|
.sun_family = AF_UNIX,
|
|
.sun_path = "/var/state/ifchange"
|
|
};
|
|
|
|
lsock = socket(AF_UNIX, SOCK_STREAM, 0);
|
|
if (lsock == -1)
|
|
suicide("dispatch_work - failed to create socket");
|
|
|
|
fcntl(lsock, F_SETFL, O_NONBLOCK);
|
|
|
|
(void) unlink("/var/state/ifchange");
|
|
ret = bind(lsock, (struct sockaddr *) &lsock_addr, sizeof(lsock_addr));
|
|
if (ret)
|
|
suicide("dispatch_work - failed to bind socket");
|
|
ret = chmod("/var/state/ifchange", S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
|
|
if (ret)
|
|
suicide("dispatch_work - failed to chmod socket");
|
|
ret = listen(lsock, SOCK_QUEUE);
|
|
if (ret)
|
|
suicide("dispatch_work - failed to listen on socket");
|
|
|
|
return lsock;
|
|
}
|
|
|
|
static void accept_conns(int *lsock)
|
|
{
|
|
int ret;
|
|
struct sockaddr_un sock_addr;
|
|
socklen_t sock_len = sizeof(sock_addr);
|
|
|
|
for(;;)
|
|
{
|
|
ret = accept(*lsock, (struct sockaddr *) &sock_addr, &sock_len);
|
|
if (ret != -1) {
|
|
add_sk(ret);
|
|
return;
|
|
}
|
|
switch (errno) {
|
|
case EAGAIN:
|
|
#ifdef LINUX
|
|
case ENETDOWN:
|
|
case EPROTO:
|
|
case ENOPROTOOPT:
|
|
case EHOSTDOWN:
|
|
case ENONET:
|
|
case EHOSTUNREACH:
|
|
case EOPNOTSUPP:
|
|
case ENETUNREACH:
|
|
#endif
|
|
return;
|
|
|
|
case EINTR:
|
|
continue;
|
|
|
|
case EBADF:
|
|
case ENOTSOCK:
|
|
case EINVAL:
|
|
log_line("warning: accept returned %s!\n", strerror(errno));
|
|
|
|
epoll_del(*lsock);
|
|
close(*lsock);
|
|
|
|
*lsock = get_listen();
|
|
epoll_add(*lsock);
|
|
return;
|
|
|
|
case ECONNABORTED:
|
|
case EMFILE:
|
|
case ENFILE:
|
|
log_line("warning: accept returned %s!\n", strerror(errno));
|
|
return;
|
|
|
|
default:
|
|
log_line("warning: accept returned a mysterious error: %s\n",
|
|
strerror(errno));
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
|
|
static void setup_signals()
|
|
{
|
|
sigset_t mask;
|
|
sigemptyset(&mask);
|
|
sigaddset(&mask, SIGPIPE);
|
|
sigaddset(&mask, SIGUSR1);
|
|
sigaddset(&mask, SIGUSR2);
|
|
sigaddset(&mask, SIGTSTP);
|
|
sigaddset(&mask, SIGTTIN);
|
|
sigaddset(&mask, SIGCHLD);
|
|
sigaddset(&mask, SIGHUP);
|
|
sigaddset(&mask, SIGINT);
|
|
sigaddset(&mask, SIGTERM);
|
|
if (sigprocmask(SIG_BLOCK, &mask, NULL) < 0)
|
|
suicide("sigprocmask failed");
|
|
signalFd = signalfd(-1, &mask, SFD_NONBLOCK);
|
|
if (signalFd < 0)
|
|
suicide("signalfd failed");
|
|
}
|
|
|
|
static void signal_dispatch()
|
|
{
|
|
int t, off = 0;
|
|
struct signalfd_siginfo si;
|
|
again:
|
|
t = read(signalFd, (char *)&si + off, sizeof si - off);
|
|
if (t < sizeof si - off) {
|
|
if (t < 0) {
|
|
if (t == EAGAIN || t == EWOULDBLOCK || t == EINTR)
|
|
goto again;
|
|
else
|
|
suicide("signalfd read error");
|
|
}
|
|
off += t;
|
|
}
|
|
switch (si.ssi_signo) {
|
|
case SIGINT:
|
|
case SIGTERM:
|
|
exit(EXIT_SUCCESS);
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
|
|
static void process_client_fd(int fd)
|
|
{
|
|
char buf[MAX_BUF];
|
|
int r, index, sqidx = -1;
|
|
for (int j = 0; j < SOCK_QUEUE; ++j) {
|
|
if (sks[j] == fd) {
|
|
sqidx = j;
|
|
break;
|
|
}
|
|
}
|
|
if (sqidx == -1)
|
|
suicide("epoll returned pending read for untracked fd");
|
|
|
|
idle_time[sqidx] = time(NULL);
|
|
memset(buf, '\0', sizeof buf);
|
|
|
|
r = safe_read(sks[sqidx], buf, sizeof buf / 2 - 1);
|
|
if (r == 0)
|
|
goto fail;
|
|
else if (r < 0) {
|
|
if (errno == EAGAIN || errno == EWOULDBLOCK)
|
|
return;
|
|
log_line("error reading from client fd: %s", strerror(errno));
|
|
}
|
|
|
|
/* Discard everything and close connection if we risk overflow.
|
|
* This approach is maximally conservative... worst case is that
|
|
* some client requests will get dropped. */
|
|
index = strlen(ibuf[sqidx]);
|
|
if (index + strlen(buf) > sizeof buf - 2)
|
|
goto fail;
|
|
|
|
/* Append new stream input avoiding overflow. */
|
|
strlcpy(ibuf[sqidx] + index, buf, sizeof ibuf[sqidx] - index);
|
|
|
|
/* Decompose ibuf contents onto strlist. */
|
|
index = stream_onto_list(sqidx);
|
|
|
|
/* Remove everything that we've parsed into the list. */
|
|
strlcpy(buf, ibuf[sqidx] + index, sizeof buf);
|
|
strlcpy(ibuf[sqidx], buf, sizeof ibuf[sqidx]);
|
|
|
|
/* Now we have a strlist of commands and arguments.
|
|
* Decompose and execute it. */
|
|
if (!head[sqidx])
|
|
return;
|
|
curl[sqidx] = head[sqidx];
|
|
execute_list(sqidx);
|
|
return;
|
|
fail:
|
|
epoll_del(sks[sqidx]);
|
|
close(sks[sqidx]);
|
|
new_sk(sqidx, -1);
|
|
}
|
|
|
|
/* Core function that handles connections, gathers input, and calls
|
|
* the state machine to do actual work. */
|
|
static void dispatch_work(void)
|
|
{
|
|
int lsock;
|
|
|
|
/* Initialize all structures to blank state. */
|
|
for (int i = 0; i < SOCK_QUEUE; i++)
|
|
sks[i] = -1;
|
|
initialize_if_data();
|
|
|
|
lsock = get_listen();
|
|
|
|
epollfd = epoll_create1(0);
|
|
if (epollfd == -1)
|
|
suicide("epoll_create1 failed");
|
|
epoll_add(lsock);
|
|
epoll_add(signalFd);
|
|
|
|
for (;;) {
|
|
int r = epoll_wait(epollfd, events, SOCK_QUEUE + 2, -1);
|
|
if (r == -1) {
|
|
if (errno == EINTR)
|
|
continue;
|
|
else
|
|
suicide("epoll_wait failed");
|
|
}
|
|
for (int i = 0; i < r; ++i) {
|
|
int fd = events[i].data.fd;
|
|
if (fd == lsock)
|
|
accept_conns(&lsock);
|
|
else if (fd == signalFd)
|
|
signal_dispatch();
|
|
else
|
|
process_client_fd(fd);
|
|
}
|
|
close_idle_sk();
|
|
}
|
|
}
|
|
|
|
int main(int argc, char** argv) {
|
|
int c, t;
|
|
uid_t uid = 0;
|
|
gid_t gid = 0;
|
|
char pidfile[MAX_PATH_LENGTH] = PID_FILE_DEFAULT;
|
|
char chrootd[MAX_PATH_LENGTH] = "";
|
|
char resolv_conf_d[MAX_PATH_LENGTH] = "";
|
|
char *p;
|
|
struct passwd *pws;
|
|
struct group *grp;
|
|
|
|
while (1) {
|
|
int option_index = 0;
|
|
static struct option long_options[] = {
|
|
{"detach", 0, 0, 'd'},
|
|
{"nodetach", 0, 0, 'n'},
|
|
{"pidfile", 1, 0, 'p'},
|
|
{"quiet", 0, 0, 'q'},
|
|
{"chroot", 1, 0, 'c'},
|
|
{"resolve", 1, 0, 'r'},
|
|
{"hostname", 0, 0, 'o'},
|
|
{"user", 1, 0, 'u'},
|
|
{"group", 1, 0, 'g'},
|
|
{"cuser", 1, 0, 'U'},
|
|
{"cgroup", 1, 0, 'G'},
|
|
{"cpid", 1, 0, 'P'},
|
|
{"interface", 1, 0, 'i'},
|
|
{"help", 0, 0, 'h'},
|
|
{"version", 0, 0, 'v'},
|
|
{"verbose", 0, 0, 'V'},
|
|
{0, 0, 0, 0}
|
|
};
|
|
|
|
c = getopt_long(argc, argv, "dnp:qc:r:ou:g:U:G:P:i:hvV", long_options,
|
|
&option_index);
|
|
if (c == -1)
|
|
break;
|
|
|
|
switch (c) {
|
|
|
|
case 'h':
|
|
printf(
|
|
"ifchd %s, if change daemon. Licensed under GNU GPL.\n", IFCHD_VERSION);
|
|
printf(
|
|
"Copyright (C) 2004-2011 Nicholas J. Kain\n"
|
|
"Usage: ifchd [OPTIONS]\n"
|
|
" -d, --detach detach from TTY and daemonize\n"
|
|
" -n, --nodetach stay attached to TTY\n"
|
|
" -q, --quiet don't print to std(out|err) or log\n"
|
|
" -c, --chroot path where ifchd should chroot\n"
|
|
" -r, --resolve path to resolv.conf or equiv\n"
|
|
" -o, --hostname allow dhcp to set machine hostname\n"
|
|
" -p, --pidfile pidfile path\n");
|
|
printf(
|
|
" -u, --user user name that ifchd should run as\n"
|
|
" -g, --group group name that ifchd should run as\n"
|
|
" -U, --cuser user name of clients\n"
|
|
" -G, --cgroup group name of clients\n"
|
|
" -P, --cpid process id of client\n"
|
|
" -i, --interface ifchd clients may modify this interface\n"
|
|
" -V, --verbose log detailed messages\n"
|
|
" -h, --help print this help and exit\n"
|
|
" -v, --version print version information and exit\n");
|
|
exit(EXIT_FAILURE);
|
|
break;
|
|
|
|
case 'v':
|
|
printf(
|
|
"ifchd %s, if change daemon. Licensed under GNU GPL.\n", IFCHD_VERSION);
|
|
printf(
|
|
"Copyright (C) 2004-2011 Nicholas J. Kain\n"
|
|
"This is free software; see the source for copying conditions. There is NO\n"
|
|
"WARRANTY; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n");
|
|
exit(EXIT_FAILURE);
|
|
break;
|
|
|
|
case 'd':
|
|
gflags_detach = 1;
|
|
break;
|
|
|
|
case 'n':
|
|
gflags_detach = 0;
|
|
break;
|
|
|
|
case 'q':
|
|
gflags_quiet = 1;
|
|
break;
|
|
|
|
case 'c':
|
|
strlcpy(chrootd, optarg, MAX_PATH_LENGTH);
|
|
break;
|
|
|
|
case 'p':
|
|
strlcpy(pidfile, optarg, MAX_PATH_LENGTH);
|
|
break;
|
|
|
|
case 'r':
|
|
strlcpy(resolv_conf_d, optarg, MAX_PATH_LENGTH);
|
|
break;
|
|
|
|
case 'o':
|
|
allow_hostname = 1;
|
|
break;
|
|
|
|
case 'u':
|
|
t = (unsigned int) strtol(optarg, &p, 10);
|
|
if (*p != '\0') {
|
|
pws = getpwnam(optarg);
|
|
if (pws) {
|
|
uid = (int)pws->pw_uid;
|
|
if (!gid)
|
|
gid = (int)pws->pw_gid;
|
|
} else suicide("FATAL - Invalid uid specified.");
|
|
} else
|
|
uid = t;
|
|
break;
|
|
|
|
case 'g':
|
|
t = (unsigned int) strtol(optarg, &p, 10);
|
|
if (*p != '\0') {
|
|
grp = getgrnam(optarg);
|
|
if (grp) {
|
|
gid = (int)grp->gr_gid;
|
|
} else
|
|
suicide("FATAL - Invalid gid specified.");
|
|
} else
|
|
gid = t;
|
|
break;
|
|
|
|
case 'U':
|
|
t = (unsigned int) strtol(optarg, &p, 10);
|
|
if (*p != '\0') {
|
|
pws = getpwnam(optarg);
|
|
if (pws) {
|
|
peer_uid = (int)pws->pw_uid;
|
|
if (!peer_gid)
|
|
peer_gid = (int)pws->pw_gid;
|
|
} else
|
|
suicide("FATAL - Invalid uid specified.");
|
|
} else
|
|
peer_uid = t;
|
|
break;
|
|
|
|
case 'G':
|
|
t = (unsigned int) strtol(optarg, &p, 10);
|
|
if (*p != '\0') {
|
|
grp = getgrnam(optarg);
|
|
if (grp) {
|
|
peer_gid = (int)grp->gr_gid;
|
|
} else
|
|
suicide("FATAL - Invalid gid specified.");
|
|
} else
|
|
peer_gid = t;
|
|
break;
|
|
|
|
case 'P':
|
|
t = (unsigned int) strtol(optarg, &p, 10);
|
|
if (*p == '\0')
|
|
peer_pid = t;
|
|
break;
|
|
|
|
case 'i':
|
|
add_permitted_if(optarg);
|
|
break;
|
|
|
|
case 'V':
|
|
gflags_verbose = 1;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (getuid())
|
|
suicide("FATAL - I need root for CAP_NET_ADMIN and chroot!");
|
|
|
|
if (gflags_detach)
|
|
if (daemon(0,0)) {
|
|
log_line("FATAL - detaching fork failed\n");
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
|
|
if (file_exists(pidfile, "w") == -1) {
|
|
log_line("FATAL - cannot open pidfile for write!");
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
write_pid(pidfile);
|
|
|
|
umask(077);
|
|
setup_signals();
|
|
|
|
/* If we are requested to update resolv.conf, preopen the fd before
|
|
* we drop root privileges, making sure that if we create
|
|
* resolv.conf, it will be world-readable.
|
|
*/
|
|
if (strncmp(resolv_conf_d, "", MAX_PATH_LENGTH)) {
|
|
umask(022);
|
|
resolv_conf_fd = open(resolv_conf_d, O_RDWR | O_CREAT, 644);
|
|
umask(077);
|
|
if (resolv_conf_fd == -1) {
|
|
suicide("FATAL - unable to open resolv.conf");
|
|
}
|
|
}
|
|
|
|
if (!strncmp(chrootd, "", MAX_PATH_LENGTH))
|
|
suicide("FATAL - No chroot path specified. Refusing to run.");
|
|
|
|
/* Note that failure cases are handled by called fns. */
|
|
imprison(chrootd);
|
|
set_cap(uid, gid, "cap_net_admin=ep");
|
|
drop_root(uid, gid);
|
|
|
|
/* Cover our tracks... */
|
|
memset(chrootd, '\0', sizeof(chrootd));
|
|
memset(resolv_conf_d, '\0', sizeof(resolv_conf_d));
|
|
memset(pidfile, '\0', sizeof(pidfile));
|
|
|
|
dispatch_work();
|
|
|
|
/* Explicitly freed so memory debugger output has less static. */
|
|
for (c=0; c<SOCK_QUEUE; ++c) {
|
|
free_strlist(head[c]);
|
|
free_strlist(namesvrs[c]);
|
|
free_strlist(domains[c]);
|
|
}
|
|
|
|
exit(EXIT_SUCCESS);
|
|
}
|