tests/bandwidth-server-many-up.c

   1 /*
   2  * Copyright © 2009-2010 Stéphane Raimbault <stephane.raimbault@gmail.com>
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include <stdio.h>
  19 #include <unistd.h>
  20 #include <string.h>
  21 #include <stdlib.h>
  22 #include <errno.h>
  23 #include <signal.h>
  24
  25 #include <modbus.h>
  26
  27 #if defined(_WIN32)
  28 #include <ws2tcpip.h>
  29 #else
  30 #include <sys/socket.h>
  31 #include <netinet/in.h>
  32 #include <arpa/inet.h>
  33 #endif
  34
  35 #define NB_CONNECTION    5
  36
  37 modbus_t *ctx = NULL;
  38 int server_socket = -1;
  39 modbus_mapping_t *mb_mapping;
  40
  41 static void close_sigint(int dummy)
  42 {
  43     if (server_socket != -1) {
  44         close(server_socket);
  45     }
  46     modbus_free(ctx);
  47     modbus_mapping_free(mb_mapping);
  48
  49     exit(dummy);
  50 }
  51
  52 int main(void)
  53 {
  54     uint8_t query[MODBUS_TCP_MAX_ADU_LENGTH];
  55     int master_socket;
  56     int rc;
  57     fd_set refset;
  58     fd_set rdset;
  59     /* Maximum file descriptor number */
  60     int fdmax;
  61
  62     ctx = modbus_new_tcp("127.0.0.1", 1502);
  63
  64     mb_mapping = modbus_mapping_new(MODBUS_MAX_READ_BITS, 0,
  65                                     MODBUS_MAX_READ_REGISTERS, 0);
  66     if (mb_mapping == NULL) {
  67         fprintf(stderr, "Failed to allocate the mapping: %s\n",
  68                 modbus_strerror(errno));
  69         modbus_free(ctx);
  70         return -1;
  71     }
  72
  73     server_socket = modbus_tcp_listen(ctx, NB_CONNECTION);
  74
  75     signal(SIGINT, close_sigint);
  76
  77     /* Clear the reference set of socket */
  78     FD_ZERO(&refset);
  79     /* Add the server socket */
  80     FD_SET(server_socket, &refset);
  81
  82     /* Keep track of the max file descriptor */
  83     fdmax = server_socket;
  84
  85     for (;;) {
  86         rdset = refset;
  87         if (select(fdmax+1, &rdset, NULL, NULL, NULL) == -1) {
  88             perror("Server select() failure.");
  89             close_sigint(1);
  90         }
  91
  92         /* Run through the existing connections looking for data to be
  93          * read */
  94         for (master_socket = 0; master_socket <= fdmax; master_socket++) {
  95
  96             if (!FD_ISSET(master_socket, &rdset)) {
  97                 continue;
  98             }
  99
 100             if (master_socket == server_socket) {
 101                 /* A client is asking a new connection */
 102                 socklen_t addrlen;
 103                 struct sockaddr_in clientaddr;
 104                 int newfd;
 105
 106                 /* Handle new connections */
 107                 addrlen = sizeof(clientaddr);
 108                 memset(&clientaddr, 0, sizeof(clientaddr));
 109                 newfd = accept(server_socket, (struct sockaddr *)&clientaddr, &addrlen);
 110                 if (newfd == -1) {
 111                     perror("Server accept() error");
 112                 } else {
 113                     FD_SET(newfd, &refset);
 114
 115                     if (newfd > fdmax) {
 116                         /* Keep track of the maximum */
 117                         fdmax = newfd;
 118                     }
 119                     printf("New connection from %s:%d on socket %d\n",
 120                            inet_ntoa(clientaddr.sin_addr), clientaddr.sin_port, newfd);
 121                 }
 122             } else {
 123                 modbus_set_socket(ctx, master_socket);
 124                 rc = modbus_receive(ctx, query);
 125                 if (rc > 0) {
 126                     modbus_reply(ctx, query, rc, mb_mapping);
 127                 } else if (rc == -1) {
 128                     /* This example server in ended on connection closing or
 129                      * any errors. */
 130                     printf("Connection closed on socket %d\n", master_socket);
 131                     close(master_socket);
 132
 133                     /* Remove from reference set */
 134                     FD_CLR(master_socket, &refset);
 135
 136                     if (master_socket == fdmax) {
 137                         fdmax--;
 138                     }
 139                 }
 140             }
 141         }
 142     }
 143
 144     return 0;
 145 }