/*

  *  Copyright (C) 2013-2019 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
  *  Copyright (C) 2007-2013 Sourcefire, Inc.

  *
  *  Authors: Tomasz Kojm, Török Edvin

  *
  *  This program is free software; you can redistribute it and/or modify

  *  it under the terms of the GNU General Public License version 2 as
  *  published by the Free Software Foundation.

  *
  *  This program is distributed in the hope that it will be useful,
  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  *  GNU General Public License for more details.
  *
  *  You should have received a copy of the GNU General Public License
  *  along with this program; if not, write to the Free Software

  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  *  MA 02110-1301, USA.

  */
 

 #if HAVE_CONFIG_H
 #include "clamav-config.h"
 #endif
 

 #include <stdio.h>
 #include <string.h>
 #include <sys/types.h>

 #ifdef HAVE_UNISTD_H
 #include <unistd.h>
 #endif

 #ifndef _WIN32

 #include <sys/socket.h>
 #include <netinet/in.h>

 #include <arpa/inet.h>

 #include <netdb.h>

 #endif

 #include <errno.h>

 #include "libclamav/clamav.h"
 

 #include "shared/optparser.h"

 #include "shared/output.h"

 #include "shared/misc.h"

 #include "others.h"
 #include "server.h"

 #include "tcpserver.h"

 int tcpserver(int **lsockets, unsigned int *nlsockets, char *ipaddr, const struct optstruct *opts)

 {

     struct addrinfo hints, *info, *p;

     char host[NI_MAXHOST], serv[NI_MAXSERV];

     int *sockets;

     int sockfd = 0, backlog;

     int *t;
     char *estr, port[10];
     int yes = 1;
     int res;

     unsigned int i = 0;
     int num_fd;

     sockets = *lsockets;

     num_fd = sd_listen_fds(0);

     if (num_fd > 2) {

         logg("!TCP: Received more than two file descriptors from systemd.\n");
         return -1;

     } else if (num_fd > 0) {

         /* use socket passed by systemd */
         int i;

         for (i = 0; i < num_fd; i += 1) {

             sockfd = SD_LISTEN_FDS_START + i;

             if (sd_is_socket(sockfd, AF_INET, SOCK_STREAM, 1) == 1) {

                 /* correct socket */
                 logg("#TCP: Received AF_INET SOCK_STREAM socket from systemd.\n");
                 break;

             } else if (sd_is_socket(sockfd, AF_INET6, SOCK_STREAM, 1) == 1) {

                 /* correct socket */
                 logg("#TCP: Received AF_INET6 SOCK_STREAM socket from systemd.\n");
                 break;

             } else {

                 /* wrong socket */
                 sockfd = -2;
             }
         }

         if (sockfd == -2) {

             logg("#TCP: No tcp AF_INET/AF_INET6 SOCK_STREAM socket received from systemd.\n");
             return -2;
         }
 
         t = realloc(sockets, sizeof(int) * (*nlsockets + 1));
         if (!(t)) {
             return -1;
         }
         sockets = t;
 
         sockets[*nlsockets] = sockfd;
         (*nlsockets)++;
         *lsockets = sockets;
         return 0;
     }
 
     /* create socket */

     snprintf(port, sizeof(port), "%lld", optget(opts, "TCPSocket")->numarg);

     memset(&hints, 0x00, sizeof(struct addrinfo));

     hints.ai_family   = AF_UNSPEC;

     hints.ai_socktype = SOCK_STREAM;

     hints.ai_flags    = AI_PASSIVE;

 #ifdef AI_ADDRCONFIG
     hints.ai_flags |= AI_ADDRCONFIG;

 #endif
 

     if ((res = getaddrinfo(ipaddr, port, &hints, &info))) {

         logg("!TCP: getaddrinfo failed: %s\n", gai_strerror(res));

         return -1;

     }

     for (p = info; p != NULL; p = p->ai_next, i++) {

         t = realloc(sockets, sizeof(int) * (*nlsockets + 1));
         if (!(t)) {

             for (i = 0; i < *nlsockets; i++)

                 close(sockets[i]);
 

             return -1;
         }
         sockets = t;
 
         if ((sockfd = socket(p->ai_family, p->ai_socktype, p->ai_protocol)) == -1) {
             estr = strerror(errno);
             logg("!TCP: socket() error: %s\n", estr);
             continue;
         }
 

         if (setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, (void *)&yes, sizeof(yes)) == -1) {

             logg("!TCP: setsocktopt(SO_REUSEADDR) error: %s\n", strerror(errno));
         }
 

 #ifdef IPV6_V6ONLY
         if (p->ai_family == AF_INET6 &&
             setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY, &yes, sizeof(yes)) == -1) {
             estr = strerror(errno);
             logg("!TCP: setsocktopt(IPV6_V6ONLY) error: %s\n", estr);
         }
 #endif /* IPV6_V6ONLY */
 

 #ifdef HAVE_GETNAMEINFO

         if ((res = getnameinfo(p->ai_addr, p->ai_addrlen, host, sizeof(host),

                                serv, sizeof(serv), NI_NUMERICHOST | NI_NUMERICSERV))) {

             logg("!TCP: getnameinfo failed: %s\n", gai_strerror(res));
             host[0] = '\0';
             serv[0] = '\0';
         }

 #else

         if (ipaddr) {
             strncpy(host, ipaddr, sizeof(host));
             host[sizeof(host) - 1] = '\0';
         } else
             host[0] = '\0';

         snprintf(serv, sizeof(serv), "%u", (unsigned int)(optget(opts, "TCPSocket")->numarg));
 #endif

         if (bind(sockfd, p->ai_addr, p->ai_addrlen) == -1) {

             estr = strerror(errno);

             logg("!TCP: Cannot bind to [%s]:%s: %s\n", host, serv, estr);

             closesocket(sockfd);

             continue;
         }

         logg("#TCP: Bound to [%s]:%s\n", host, serv);

 
         backlog = optget(opts, "MaxConnectionQueueLength")->numarg;
         logg("#TCP: Setting connection queue length to %d\n", backlog);
 

         if (listen(sockfd, backlog) == -1) {

             estr = strerror(errno);

             logg("!TCP: Cannot listen on [%s]:%s: %s\n", host, serv, estr);

             closesocket(sockfd);
 
             continue;
         }
 
         sockets[*nlsockets] = sockfd;
         (*nlsockets)++;

     }
 

     freeaddrinfo(info);
     *lsockets = sockets;
 
     return 0;

 }