I'm completely stumped on this. An AIX machine I'm working on is attempting to send email, but the SMTP connection is failing. I have no idea what this code does or if it should even work. If someone could give me a hand, or a suggestion on what else to use, I would appreciate it.
I cannot debug this - when I step into connect() it appears to step-over.
#if INCL_WINSOCK_API_PROTOTYPES
WINSOCK_API_LINKAGE
int
WSAAPI
connect(
IN SOCKET s,
__in_bcount(namelen) const struct sockaddr FAR * name,
IN int namelen
);
#endif /* INCL_WINSOCK_API_PROTOTYPES */
I would try printing the value of "errno" to find out why the socket didnt connect.
I would also have a look at "the_socket" to make sure it is >= 0.
Then I would also look at the contents of sa_in (which should be a struct sockaddr_in)
My guess from the WINSOCK comment is that this is a ported windows application. As such I believe they can be different in the way that the sa_in is formed (intel is little endian and power is big endian, so for example a missing "htons" on the port or something like that could make a difference on only one platform)
None of that winsock stuff matters unless INCL_WINSOCK_API_PROTOTYPES is defined -- it's probably safe to ignore. Windows does in fact have a socket API that vaguely resembles the expected standard, so the code could have been ported as citaylor noted...
After it fails you can try perror("connection failed"); and it should print something like connection failed: no route to host or whatever to stderr.
connect() is usually a system call, not a function, meaning there's nothing happening inside your process to trace during connect() -- it's asleep. Some special instruction or software interrupt has transferred control to the kernel, which will wake it back up when its done.
For more detail on the connect call, try man 2 connect
---------- Post updated at 02:22 PM ---------- Previous update was at 02:06 PM ----------
const char *host="smtp.whatever.com";
short int port=25; // standard smtp port
int sockfd, n;
struct sockaddr_in serv_addr;
struct hostent *server;
sockfd=socket(AF_INET, SOCK_STREAM, 0);
server=gethostbyname(host); // look up host's IP address
// copy the IP address and port into the address structure
memset(&serv_addr, 0, sizeof(serv_addr));
serv_addr.sin_family=AF_INET;
bcopy(server->h_addr,&serv_addr.sin_addr.s_addr, server->h_length);
serv_addr.sin_port=htons(port); // htons() puts it in the right byte order
connect(sockfd, &serv_addr, sizeof(serv_addr));
RETURN VALUES
Upon successful completion, a value of 0 is returned. Otherwise, a value of -1 is returned and the global inte-
ger variable errno is set to indicate the error.
Yes, and the perror() command I suggested above checks errno to tell what it should print. errno is a global variable that's set by system calls, so when most any system call returns an error, perror can tell you what it is.
bcopy() doesn't show up as a usable method - I did find a reference to memcpy, but I get an invalid void 1st parameter error. Any idea what to try? I made sure I had #include <strings.h>
bcopy works like bcopy(source, dest, length);
memcpy works like memcpy(dest, source, length);
So you have to swap the first two. Otherwise they're equivalent. I considered replacing that for you but decided I shouldn't mess with the original code too much. Sorry.
"invalid void first parameter" is a new one on me. functions like memcpy and bcopy usually take void * so you can feed them any kind of pointer without the compiler whining. I suspect something else is wrong, maybe it doesn't like how I'm using the structure members. Can you print the exact line you have and the exact error you get?
[edit] It's string.h, not strings.h. That might do it.
again. On my windows box, s_addr shows up as 364431568
---------- Post updated at 05:27 PM ---------- Previous update was at 05:25 PM ----------
heyooo, I think it worked this time. I tried h_addr instead of h_addrtype like you suggested, and it took. I get this now, but I don't think it's anything to be concerned about?
Never use Windows documentation to program an AIX system! When I said it only vaguely adhered to the standard, I wasn't kidding. It's a bit skewed compared to what you get on a UNIX system.
Do you still have it as strings.h instead of string.h? That might cause that.
Those were included before I started changing anything - if this works (I pray it does) I plan on going back and doing a bit of cleanup in this file. Hard to tell how old it is. I'll let you know how the results turn out (should know in the next hour or so)!
I didn't recompile everything I should have - going to have to try again tomorrow. It will take another hour or so to shutdown the servers, recompile, and reboot them. I'll keep you updated though. Thanks again for the help!
---------- Post updated 01-21-11 at 11:51 AM ---------- Previous update was 01-20-11 at 06:54 PM ----------
So unfortunately, I'm still getting a -1 returned from connect(). Here's my full code:
int
connection::get_connected (char * hostname, char * service)
{
struct hostent * hostentry; /* from gethostbyname */
struct servent * serventry; /* from getservbyname */
unsigned long ip_address;
struct sockaddr_in sa_in;
int our_port;
struct linger NoLinger;
int retval, err_code;
unsigned long ioctl_blocking = 1;
char message[512];
// if the ctor couldn't get a buffer
if (!in_buffer || !out_buffer)
return (ERR_CANT_MALLOC);
// --------------------------------------------------
// resolve the service name
//
// If they've specified a number, just use it.
if (gensock_is_a_number (service))
{
char * tail;
our_port = (int) strtol (service, &tail, 10);
if (tail == service)
{
return (ERR_CANT_RESOLVE_SERVICE);
}
else
{
our_port = htons (our_port);
}
}
else
{
// we have a name, we must resolve it.
serventry = getservbyname (service, "tcp");
if (serventry)
our_port = serventry->s_port;
else
return (ERR_CANT_RESOLVE_SERVICE);
}
// --------------------------------------------------
// resolve the hostname/ipaddress
//
// Assume only hostname
// if ((ip_address = inet_addr (hostname)) != INADDR_NONE) {
// sa_in.sin_addr.s_addr = ip_address;
// }
// else {
if ((hostentry = gethostbyname(hostname)) == NULL)
{
return (ERR_CANT_RESOLVE_HOSTNAME);
}
sa_in.sin_addr.s_addr = *(long *)hostentry->h_addr;
// }
// --------------------------------------------------
// get a socket
//
if ((the_socket = socket(AF_INET, SOCK_STREAM, 0)) == INVALID_SOCKET)
{
return (ERR_CANT_GET_SOCKET);
}
sa_in.sin_family = AF_INET;
sa_in.sin_port = our_port;
// set socket options. DONTLINGER will give us a more graceful disconnect
NoLinger.l_onoff = 0;
setsockopt(the_socket,
SOL_SOCKET,
SO_LINGER,
(char *) &NoLinger, sizeof(NoLinger));
// get a connection
memset(&sa_in, 0, sizeof(sa_in));
memcpy(&sa_in.sin_addr.s_addr, hostentry->h_addr, hostentry->h_length);
sa_in.sin_port=htons(our_port);
retval = connect (the_socket, (struct sockaddr *) & sa_in,
sizeof(sa_in));
if (retval == SOCKET_ERROR)
{
return (ERR_CANT_CONNECT);
}
#ifdef HA
// Make this a non-blocking socket
fcntl (the_socket, F_SETFL, O_NDELAY);
// make the FD_SET and timeout structures for later operations...
#endif
FD_ZERO (&fds);
FD_SET (the_socket, &fds);
// normal timeout, can be changed by the wait option.
timeout.tv_sec = 0;
timeout.tv_usec = 0;
return (0);
}
I'm lost at this point.
---------- Post updated at 12:03 PM ---------- Previous update was at 12:02 PM ----------
I should mention also that when I try to do 'print hostentry->h_addr' it says that's not a valid member... but it compiles fine with gmake. So I'm not sure.
I am also mystified. We've given you several methods of getting the actual error but you haven't used them. Until you do, your guess is as good as mine.
that means 'directory not empty'. It's likely totally unrelated to the bit of code you're playing with. If you put a perror() too late, errno could have been trashed by any other system call that happened along the way.
The code 78 you get makes a lot more sense: 'connection timed out' on AIX 4.3 and 5.1. It's also what perror() would be printing for you.
So the next obvious thing would be trying to connect to the server and port you're giving it by hand, with telnet or something. Maybe it really is not letting you connect on that port.
Can you post your code again? I have no idea what it looks like now.
It's a bit skewed compared to what you get on a UNIX system.