hush/libbb/xconnect.c
Glenn L McGrath 036dbaa082 Modify bb_lookup_port to allow the protocol to be specified, allowing
/etc/services support for inetd, netcat and tftp.
2004-01-17 05:03:31 +00:00

72 lines
1.8 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Utility routines.
*
* Connect to host at port using address resolusion from getaddrinfo
*
*/
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <errno.h>
#include <netdb.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include "libbb.h"
/* Return network byte ordered port number for a service.
* If "port" is a number use it as the port.
* If "port" is a name it is looked up in /etc/services, if it isnt found return
* default_port
*/
unsigned short bb_lookup_port(const char *port, const char *protocol, unsigned short default_port)
{
unsigned short port_nr = htons(default_port);
if (port) {
char *endptr;
int old_errno;
long port_long;
/* Since this is a lib function, we're not allowed to reset errno to 0.
* Doing so could break an app that is deferring checking of errno. */
old_errno = errno;
errno = 0;
port_long = strtol(port, &endptr, 10);
if (errno != 0 || *endptr!='\0' || endptr==port || port_long < 0 || port_long > 65535) {
struct servent *tserv = getservbyname(port, protocol);
if (tserv) {
port_nr = tserv->s_port;
}
} else {
port_nr = htons(port_long);
}
errno = old_errno;
}
return port_nr;
}
void bb_lookup_host(struct sockaddr_in *s_in, const char *host)
{
struct hostent *he;
memset(s_in, 0, sizeof(struct sockaddr_in));
s_in->sin_family = AF_INET;
he = xgethostbyname(host);
memcpy(&(s_in->sin_addr), he->h_addr_list[0], he->h_length);
}
int xconnect(struct sockaddr_in *s_addr)
{
int s = socket(AF_INET, SOCK_STREAM, 0);
if (connect(s, (struct sockaddr_in *)s_addr, sizeof(struct sockaddr_in)) < 0)
{
bb_perror_msg_and_die("Unable to connect to remote host (%s)",
inet_ntoa(s_addr->sin_addr));
}
return s;
}