sp_sendmsg

Description

Sends a message to a User Datagram Protocol (UDP) port.

Syntax

sp_sendmsg ip_address, port_number, message

Parameters

Examples

Example 1

sp_sendmsg "120.10.20.5", 3456, "Hello World"

Usage

• sp_sendmsg is not supported on Windows NT.

• To enable the use of UDP messaging, a system security officer must set the configuration parameter allow sendmsg to 1.

• No security checks are performed with sp_sendmsg. Sybase strongly recommends caution when using sp_sendmsg to send sensitive information across the network. By enabling this functionality, the user accepts any security problems which result from its use.

• This sample C program listens on a port that you specify and echoes the messages it receives. For example, to receive the sp_sendmsg calls for Example 1, use:

  updmon 3456
  #include <stdlib.h>
  #include <stdio.h>
  #include <sys/types.h>
  #include <sys/socket.h>
  #include <netinet/in.h>
  #include <arpa/inet.h>
  #include <unistd.h>
  #include <fcntl.h>
  
  main(argc, argv)
  int argc; char *argv[];
  {
          struct sockaddr_in sadr;
          int portnum,sck,dummy,msglen;
          char msg[256];
  
          if (argc < 2) {
                  printf(“Usage: udpmon <udp portnum>\n”);
                  exit(1);
          }
  
          if ((portnum=atoi(argv[1])) < 1) {
                  printf("Invalid udp portnum\n");
                  exit(1);
          }
  
          if ((sck=socket(AF_INET,SOCK_DGRAM,IPPROTO_UDP)) < 0) {
                  printf("Couldn't create socket\n");
                  exit(1);
          }
  
          sadr.sin_family = AF_INET;
          sadr.sin_addr.s_addr = inet_addr("0.0.0.0");
          sadr.sin_port = portnum;
  
          if (bind(sck,&sadr,sizeof(sadr)) < 0) {
                  printf("Couldn't bind requested udp port\n");
                  exit(1);
          }
  
          for (;;)
          {
                  if((msglen=recvfrom(sck,msg,sizeof(msg),0,NULL,&dummy)) < 0)
                          printf("Couldn't recvfrom() from udp port\n");
                  printf("%.*s\n", msglen, msg);
          }
  }
  

Permissions

Any user can execute sp_sendmsg.

Auditing

Values in event and extrainfo columns from the sysaudits table are:

See also