Specifications

Page 32 Remote Procedure Call Programming Guide
#include <stdio.h>
#include <rpc/rpc.h>
#include <sys/socket.h>
gettransient(proto, vers, sockp)
int proto, vers, *sockp;
{
static int prognum = 0x40000000;
int s, len, socktype;
struct sockaddr_in addr;
switch(proto) {
case IPPROTO_UDP:
socktype = SOCK_DGRAM;
break;
case IPPROTO_TCP:
socktype = SOCK_STREAM;
break;
default:
fprintf(stderr, "unknown protocol type\n");
return 0;
}
if (*sockp == RPC_ANYSOCK) {
if ((s = socket(AF_INET, socktype, 0)) < 0) {
perror("socket");
return (0);
}
*sockp = s;
}
else
s = *sockp;
addr.sin_addr.s_addr = 0;
addr.sin_family = AF_INET;
addr.sin_port = 0;
len = sizeof(addr);
/*
* may be already bound, so don’t check for error
*/
bind(s, &addr, len);
if (getsockname(s, &addr, &len)< 0) {
perror("getsockname");
return (0);
}
while (!pmap_set(prognum++, vers, proto,
ntohs(addr.sin_port))) continue;
return (prognum-1);
}
Note: The call to ntohs() is necessary to ensure that the port number in addr.sin_port, which is in network
byte order, is passed in host byte order (as pmap_set() expects). See the byteorder(3N) man page for more
details on the conversion of network addresses from network to host byte order.