man/man3socket/connect.3socket

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <inttypes.h>
#include <stdio.h>
#include <strings.h>
#include <stdlib.h>
#include <errno.h>
#include <port.h>
#include <unistd.h>
#include <assert.h>

int
main(int argc, char *argv[])
{
 char *eptr;
 long port;
 int sock, ret, eport;
 struct sockaddr_in6 sin6;

 if (argc != 3) {
 fprintf(stderr, "connect: <IP> <port>\\n");
 return (1);
 }

 bzero(&sin6, sizeof (struct sockaddr_in6));
 sin6.sin6_family = AF_INET6;

 /*
 * Try to parse as an IPv6 address and then try v4.
 */
 ret = inet_pton(AF_INET6, argv[1], &sin6.sin6_addr);
 if (ret == -1) {
 perror("inet_pton");
 return (1);
 } else if (ret == 0) {
 struct in_addr v4;
 ret = inet_pton(AF_INET, argv[1], &v4);
 if (ret == -1) {
 perror("inet_pton");
 return (1);
 } else if (ret == 0) {
 fprintf(stderr, "connect: %s is not a valid "
 "IPv4 or IPv6 address\\n", argv[1]);
 return (1);
 }
 /* N.B. Not a portable macro */
 IN6_INADDR_TO_V4MAPPED(&v4, &sin6.sin6_addr);
 }

 errno = 0;
 port = strtol(argv[2], &eptr, 10);
 if (errno != 0 || *eptr != '\0') {
 fprintf(stderr, "failed to parse port %s\\n", argv[2]);
 return (1);
 }
 if (port <= 0 || port > UINT16_MAX) {
 fprintf(stderr, "invalid port: %ld\\n", port);
 return (1);
 }
 sin6.sin6_port = htons(port);

 sock = socket(AF_INET6, SOCK_STREAM | SOCK_NONBLOCK, 0);
 if (sock < 0) {
 perror("socket");
 return (1);
 }

 eport = port_create();
 if (eport < 0) {
 perror("port_create");
 (void) close(sock);
 return (1);
 }

 ret = connect(sock, (struct sockaddr *)&sin6,
 sizeof (struct sockaddr_in6));
 if (ret != 0 && errno != EINPROGRESS && errno != EINTR) {
 perror("connect");
 (void) close(sock);
 (void) close(eport);
 return (1);
 }

 if (ret != 0) {
 port_event_t pe;
 int err;
 socklen_t sz = sizeof (err);
 if (port_associate(eport, PORT_SOURCE_FD, sock, POLLOUT,
 NULL) != 0) {
 perror("port_associate");
 (void) close(sock);
 (void) close(eport);
 return (1);
 }
 if (port_get(eport, &pe, NULL) != 0) {
 perror("port_get");
 (void) close(sock);
 (void) close(eport);
 return (1);
 }
 assert(pe.portev_source == PORT_SOURCE_FD);
 assert(pe.portev_object == (uintptr_t)sock);
 if (getsockopt(sock, SOL_SOCKET, SO_ERROR, &err, &sz) != 0) {
 perror("getsockopt");
 (void) close(sock);
 (void) close(eport);
 return (1);
 }
 if (err != 0) {
 /* Asynch connect failed */
 fprintf(stderr, "asnchronous connect: %s\\n",
 strerror(err));
 (void) close(sock);
 (void) close(eport);
 return (1);
 }
 }

 /* Read and write to the socket and then clean up */

 return (0);
}