I have C code that listens on a port, but it is listening on the wrong port.
This is defined in a .h file:
#define PHANTASIA_PORT 2101
The socket:
int the_socket, error, on=1;
/* create a socket */
errno = 0;
if ((the_socket=socket(AF_INET, SOCK_STREAM, 0)) == -1) {
sprintf(error_msg,
"[0.0.0.0:?] Socket creation failed in Do_init_server_socket: %s\n",
strerror(errno));
Do_log_error(error_msg);
exit(SOCKET_CREATE_ERROR);
}
error = setsockopt(the_socket, SOL_SOCKET, SO_REUSEADDR,
(char *) &on, sizeof(on));
This is how it binds:
/* set up the bind address */
bind_address.sin_family = AF_INET;
bind_address.开发者_高级运维sin_addr.s_addr = INADDR_ANY;
bind_address.sin_port = PHANTASIA_PORT;
/* bind to that socket */
error = bind(the_socket, (struct sockaddr *) &bind_address,
sizeof(bind_address));
error = listen(the_socket, SOMAXCONN);
But then when it is run, lsof reports:
phantasia 2400 root 4u IPv4 2024436 TCP *:13576 (LISTEN)
When I changed the port to 2100 in the define, it instead listened for:
phantasia 2266 root 4u IPv4 2021315 TCP *:13320 (LISTEN)
This is some old code but doesn't have any warnings or errors when compiling. Maybe something is going over my head. I have a debug log when it binds and it reports it binds to port 2101.
Replace PHANTASIA_PORT
with htons(PHANTASIA_PORT)
.
Use htons
function when specifying the port number.
So this line:
bind_address.sin_port = PHANTASIA_PORT;
Should be:
bind_address.sin_port = htons(PHANTASIA_PORT);
htons
is a function that will convert host integer numbers to network integer numbers, fixing the endianness (HI-LO/LO-HI byte order within integer) of them if necessary.
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