proxysql/lib/network.cpp

#include "proxysql.h"

/*
 * create a socket and listen on a specified IP and port
 * returns the socket
 */
int listen_on_port(char *ip, uint16_t port, int backlog, bool reuseport) {
	int rc, arg_on = 1;
	struct addrinfo hints;
	memset(&hints,0,sizeof(hints));
	hints.ai_flags = AI_PASSIVE;
	hints.ai_family = AF_UNSPEC;
	hints.ai_socktype = SOCK_STREAM;
	hints.ai_protocol = IPPROTO_TCP;
	struct addrinfo *next, *ai;
	char port_string[NI_MAXSERV];
	int sd = -1;

	snprintf(port_string, sizeof(port_string), "%d", port);
	rc = getaddrinfo(ip, port_string, &hints, &ai);
	if (rc) {
		proxy_error("getaddrinfo(): %s\n", gai_strerror(rc));
		return -1;
	}

	for (next = ai; next != NULL; next = next->ai_next) {
		if ((sd = socket(next->ai_family, next->ai_socktype, next->ai_protocol)) == -1) {
			proxy_error("socket() error for %s:%d: %s\n", ip, port, strerror(errno));
			sd = -1;
			continue;
		}
#ifdef IPV6_V6ONLY
		if (next->ai_family == AF_INET6) {
			if(setsockopt(sd, IPPROTO_IPV6, IPV6_V6ONLY, (char *)&arg_on, sizeof(arg_on)) == -1) 
			proxy_error("setsockopt() IPV6_V6ONLY: %s\n", gai_strerror(errno));
		}
#endif

		if (setsockopt(sd, SOL_SOCKET, SO_REUSEADDR, (char *)&arg_on, sizeof(arg_on)) == -1) {
			proxy_error("setsockopt() SO_REUSEADDR error for %s:%d: %s\n", ip, port, gai_strerror(errno));
			close(sd);
			freeaddrinfo(ai);
			return -1;
		}

#ifdef SO_REUSEPORT
  		if (reuseport) {
			if (setsockopt(sd, SOL_SOCKET, SO_REUSEPORT, (char *)&arg_on, sizeof(arg_on)) == -1) {
				proxy_error("setsockopt() SO_REUSEPORT error for %s:%d: %s\n", ip, port, gai_strerror(errno));
			}
		}
#endif /* SO_REUSEPORT */

		if (bind(sd, next->ai_addr, next->ai_addrlen) == -1) {
			//if (errno != EADDRINUSE) {
			proxy_error("bind() error for %s:%d: %s\n", ip, port, strerror(errno));
			// in case of 'EADDRNOTAVAIL' suggest a solution to user. See #1614.
			if (errno == EADDRNOTAVAIL) {
				proxy_info(
				   "Trying to 'bind()' failed due to 'EADDRNOTAVAIL'. If trying to bind to a "
				   "non-local IP address, make sure 'net.ipv4.ip_nonlocal_bind' is set to '1'\n"
				);
			}
			close(sd);
			freeaddrinfo(ai);
			return -1;
		} else {
			if (listen(sd, backlog) == -1) {
				proxy_error("listen() error for %s:%d: %s\n", ip, port, strerror(errno));
				close(sd);
				freeaddrinfo(ai);
				return -1;
			}
		}
	}

	freeaddrinfo(ai);
	// return the socket
	return sd;
}

/*
 * create a socket and listen on the specified path
 * returns the socket
 */
int listen_on_unix(char *path, int backlog) {
	struct sockaddr_un serveraddr;
	int sd;
	int r;

	// remove the socket
	r=unlink(path);
	if ( (r==-1) && (errno!=ENOENT) ) {
		proxy_error("Error unlink Unix Socket %s\n", path);
		return -1;
	}

	// create a socket
	if ( ( sd = socket(AF_UNIX, SOCK_STREAM, 0)) <0 ) {
		proxy_error("Error on creating socket: %s\n", strerror(errno));
		close(sd);
		return -1;
	}

	memset(&serveraddr, 0, sizeof(serveraddr));
	serveraddr.sun_family = AF_UNIX;
	strncpy(serveraddr.sun_path, path, sizeof(serveraddr.sun_path) - 1);

	// call bind() to bind the socket on the specified file
	if ( bind(sd, (struct sockaddr *)&serveraddr, sizeof(struct sockaddr_un)) != 0 ) {
		proxy_error("Error on bind() for Unix Socket %s: %s\n", path, strerror(errno));
		close(sd);
		return -1;
	}

	// define the backlog
	if ( listen(sd, backlog) != 0 ) {
		proxy_error("Error on listen() for Unix Socket %s: %s\n", path, strerror(errno));
		close(sd);
		return -1;
	}

	// change the permission on socket
	r=chmod(path, S_IRUSR | S_IWUSR | S_IXUSR | S_IRGRP | S_IWGRP | S_IXGRP | S_IROTH | S_IWOTH | S_IXOTH);
	return sd;
}



/*
// THIS CODE IS BEING COMMENTED BECAUSED UNUSED (probably since 2015)
//
int connect_socket(char *address, int connect_port)
{
	struct sockaddr_in a;
	int s;

	if ((s = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
		perror("socket");
		close(s);
		return -1;
	}

	memset(&a, 0, sizeof(a));
	a.sin_port = htons(connect_port);
	a.sin_family = AF_INET;

	if (!inet_aton(address, (struct in_addr *) &a.sin_addr.s_addr)) {
		perror("bad IP address format");
		close(s);
		return -1;
	}

	if (connect(s, (struct sockaddr *) &a, sizeof(a)) == -1) {
		perror("connect()");
		shutdown(s, SHUT_RDWR);
		close(s);
		return -1;
	}
	return s;
}
*/