#include "unix.h"

#include "conf.h"

static int
sock_perms(int fd)
{
	// first get group by name
	struct group *group;
	if ((group = getgrnam(SOCKETGROUP)) == NULL) {
		fprintf(stderr,"no such group: %s\n",SOCKETGROUP);
		return -1;
	}
	// set group on socket
	if (fchown(fd, -1, group.gr_gid) == -1) {
		perror("chown");
		return -1;
	}

	// get current permissions, so we can modify them.
	struct stat sb;
	if (fstat(fd, &sb) == -1) {
		perror("stat");
		return -1;
	}
	if (fchmod(fd, sb.st_mode|S_IWGRP) == -1) {
		perror("chmod");
		return -1;
	}

	return 0;
}

// takes filename, returns socket fd
// or -1 or whatever
int
unix_setup(char sockname[])
{
	unlink(sockname);

	int sock = socket(AF_UNIX, SOCK_DGRAM, 0);
	if (sock == -1) {
		perror("(unix) socket");
		return -1;
	}

	struct sockaddr_un name;
	memset(&name, 0, sizeof name);
	name.sun_family = AF_UNIX;
	strncpy(name.sun_path, SOCKETNAME, (sizeof name.sun_path)-1);
	if (bind(sock, (struct sockaddr *)&name, sizeof name) == -1) {
		perror("(unix) bind");
		return -1;
	}

	if (sock_perms(sock) == -1) {
		fprintf(stderr,"warning: couldn't correctly set up permissions on %s\n",sockname);
	}

	return sock;
}