socket_wrapper.c

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		break;
	case AF_UNIX:
		return real_socket(family, type, protocol);
	default:
		errno = EAFNOSUPPORT;
		return -1;
	}

	switch (type) {
	case SOCK_STREAM:
		break;
	case SOCK_DGRAM:
		break;
	default:
		errno = EPROTONOSUPPORT;
		return -1;
	}

	switch (protocol) {
	case 0:
		break;
	default:
		errno = EPROTONOSUPPORT;
		return -1;
	}

	fd = real_socket(AF_UNIX, type, 0);

	if (fd == -1) return -1;

	si = (struct socket_info *)calloc(1, sizeof(struct socket_info));

	si->family = family;
	si->type = type;
	si->protocol = protocol;
	si->fd = fd;

	SWRAP_DLIST_ADD(sockets, si);

	return si->fd;
}

_PUBLIC_ int swrap_accept(int s, struct sockaddr *addr, socklen_t *addrlen)
{
	struct socket_info *parent_si, *child_si;
	int fd;
	struct sockaddr_un un_addr;
	socklen_t un_addrlen = sizeof(un_addr);
	struct sockaddr_un un_my_addr;
	socklen_t un_my_addrlen = sizeof(un_my_addr);
	struct sockaddr my_addr;
	socklen_t my_addrlen = sizeof(my_addr);
	int ret;

	parent_si = find_socket_info(s);
	if (!parent_si) {
		return real_accept(s, addr, addrlen);
	}

	memset(&un_addr, 0, sizeof(un_addr));
	memset(&un_my_addr, 0, sizeof(un_my_addr));
	memset(&my_addr, 0, sizeof(my_addr));

	ret = real_accept(s, (struct sockaddr *)&un_addr, &un_addrlen);
	if (ret == -1) return ret;

	fd = ret;

	ret = sockaddr_convert_from_un(parent_si, &un_addr, un_addrlen,
				       parent_si->family, addr, addrlen);
	if (ret == -1) {
		close(fd);
		return ret;
	}

	child_si = (struct socket_info *)malloc(sizeof(struct socket_info));
	memset(child_si, 0, sizeof(*child_si));

	child_si->fd = fd;
	child_si->family = parent_si->family;
	child_si->type = parent_si->type;
	child_si->protocol = parent_si->protocol;
	child_si->bound = 1;
	child_si->is_server = 1;

	ret = real_getsockname(fd, (struct sockaddr *)&un_my_addr, &un_my_addrlen);
	if (ret == -1) {
		free(child_si);
		close(fd);
		return ret;
	}

	ret = sockaddr_convert_from_un(child_si, &un_my_addr, un_my_addrlen,
				       child_si->family, &my_addr, &my_addrlen);
	if (ret == -1) {
		free(child_si);
		close(fd);
		return ret;
	}

	child_si->myname_len = my_addrlen;
	child_si->myname = sockaddr_dup(&my_addr, my_addrlen);

	child_si->peername_len = *addrlen;
	child_si->peername = sockaddr_dup(addr, *addrlen);

	SWRAP_DLIST_ADD(sockets, child_si);

	swrap_dump_packet(child_si, addr, SWRAP_ACCEPT_SEND, NULL, 0);
	swrap_dump_packet(child_si, addr, SWRAP_ACCEPT_RECV, NULL, 0);
	swrap_dump_packet(child_si, addr, SWRAP_ACCEPT_ACK, NULL, 0);

	return fd;
}

static int autobind_start_init;
static int autobind_start;

/* using sendto() or connect() on an unbound socket would give the
   recipient no way to reply, as unlike UDP and TCP, a unix domain
   socket can't auto-assign emphemeral port numbers, so we need to
   assign it here */
static int swrap_auto_bind(struct socket_info *si)
{
	struct sockaddr_un un_addr;
	struct sockaddr_in in;
	int i;
	char type;
	int ret;
	int port;
	struct stat st;

	if (autobind_start_init != 1) {
		autobind_start_init = 1;
		autobind_start = getpid();
		autobind_start %= 50000;
		autobind_start += 10000;
	}

	un_addr.sun_family = AF_UNIX;

	switch (si->type) {
	case SOCK_STREAM:
		type = SOCKET_TYPE_CHAR_TCP;
		break;
	case SOCK_DGRAM:
		type = SOCKET_TYPE_CHAR_UDP;
		break;
	default:
		errno = ESOCKTNOSUPPORT;
		return -1;
	}

	if (autobind_start > 60000) {
		autobind_start = 10000;
	}

	for (i=0;i<1000;i++) {
		port = autobind_start + i;
		snprintf(un_addr.sun_path, sizeof(un_addr.sun_path), 
			 "%s/"SOCKET_FORMAT, socket_wrapper_dir(),
			 type, socket_wrapper_default_iface(), port);
		if (stat(un_addr.sun_path, &st) == 0) continue;
		
		ret = real_bind(si->fd, (struct sockaddr *)&un_addr, sizeof(un_addr));
		if (ret == -1) return ret;

		si->tmp_path = strdup(un_addr.sun_path);
		si->bound = 1;
		autobind_start = port + 1;
		break;
	}
	if (i == 1000) {
		errno = ENFILE;
		return -1;
	}

	memset(&in, 0, sizeof(in));
	in.sin_family = AF_INET;
	in.sin_port   = htons(port);
	in.sin_addr.s_addr = htonl(127<<24 | socket_wrapper_default_iface());
	
	si->myname_len = sizeof(in);
	si->myname = sockaddr_dup(&in, si->myname_len);
	return 0;
}


_PUBLIC_ int swrap_connect(int s, const struct sockaddr *serv_addr, socklen_t addrlen)
{
	int ret;
	struct sockaddr_un un_addr;
	struct socket_info *si = find_socket_info(s);

	if (!si) {
		return real_connect(s, serv_addr, addrlen);
	}

	if (si->bound == 0) {
		ret = swrap_auto_bind(si);
		if (ret == -1) return -1;
	}

	ret = sockaddr_convert_to_un(si, (const struct sockaddr *)serv_addr, addrlen, &un_addr, 0, NULL);
	if (ret == -1) return -1;

	swrap_dump_packet(si, serv_addr, SWRAP_CONNECT_SEND, NULL, 0);

	ret = real_connect(s, (struct sockaddr *)&un_addr, 
			   sizeof(struct sockaddr_un));

	/* to give better errors */
	if (ret == -1 && errno == ENOENT) {
		errno = EHOSTUNREACH;
	}

	if (ret == 0) {
		si->peername_len = addrlen;
		si->peername = sockaddr_dup(serv_addr, addrlen);

		swrap_dump_packet(si, serv_addr, SWRAP_CONNECT_RECV, NULL, 0);
		swrap_dump_packet(si, serv_addr, SWRAP_CONNECT_ACK, NULL, 0);
	} else {
		swrap_dump_packet(si, serv_addr, SWRAP_CONNECT_UNREACH, NULL, 0);
	}

	return ret;
}

_PUBLIC_ int swrap_bind(int s, const struct sockaddr *myaddr, socklen_t addrlen)
{
	int ret;
	struct sockaddr_un un_addr;
	struct socket_info *si = find_socket_info(s);

	if (!si) {
		return real_bind(s, myaddr, addrlen);
	}

	si->myname_len = addrlen;
	si->myname = sockaddr_dup(myaddr, addrlen);

	ret = sockaddr_convert_to_un(si, (const struct sockaddr *)myaddr, addrlen, &un_addr, 1, &si->bcast);
	if (ret == -1) return -1;

	unlink(un_addr.sun_path);

	ret = real_bind(s, (struct sockaddr *)&un_addr,
			sizeof(struct sockaddr_un));

	if (ret == 0) {
		si->bound = 1;
	}

	return ret;
}

_PUBLIC_ int swrap_listen(int s, int backlog)
{
	int ret;
	struct socket_info *si = find_socket_info(s);

	if (!si) {
		return real_listen(s, backlog);
	}

	ret = real_listen(s, backlog);

	return ret;
}

_PUBLIC_ int swrap_getpeername(int s, struct sockaddr *name, socklen_t *addrlen)
{
	struct socket_info *si = find_socket_info(s);

	if (!si) {
		return real_getpeername(s, name, addrlen);
	}

	if (!si->peername)
	{
		errno = ENOTCONN;
		return -1;
	}

	memcpy(name, si->peername, si->peername_len);
	*addrlen = si->peername_len;

	return 0;
}

_PUBLIC_ int swrap_getsockname(int s, struct sockaddr *name, socklen_t *addrlen)
{
	struct socket_info *si = find_socket_info(s);

	if (!si) {
		return real_getsockname(s, name, addrlen);
	}

	memcpy(name, si->myname, si->myname_len);
	*addrlen = si->myname_len;

	return 0;
}

_PUBLIC_ int swrap_getsockopt(int s, int level, int optname, void *optval, socklen_t *optlen)
{
	struct socket_info *si = find_socket_info(s);

	if (!si) {
		return real_getsockopt(s, level, optname, optval, optlen);
	}

	if (level == SOL_SOCKET) {
		return real_getsockopt(s, level, optname, optval, optlen);
	} 

	errno = ENOPROTOOPT;
	return -1;
}

_PUBLIC_ int swrap_setsockopt(int s, int  level,  int  optname,  const  void  *optval, socklen_t optlen)
{
	struct socket_info *si = find_socket_info(s);

	if (!si) {
		return real_setsockopt(s, level, optname, optval, optlen);
	}

	if (level == SOL_SOCKET) {
		return real_setsockopt(s, level, optname, optval, optlen);
	}

	switch (si->family) {
	case AF_INET:
		return 0;
	default:
		errno = ENOPROTOOPT;
		return -1;
	}
}

_PUBLIC_ ssize_t swrap_recvfrom(int s, void *buf, size_t len, int flags, struct sockaddr *from, socklen_t *fromlen)
{
	struct sockaddr_un un_addr;
	socklen_t un_addrlen = sizeof(un_addr);
	int ret;
	struct socket_info *si = find_socket_info(s);

	if (!si) {
		return real_recvfrom(s, buf, len, flags, from, fromlen);
	}

	/* irix 6.4 forgets to null terminate the sun_path string :-( */
	memset(&un_addr, 0, sizeof(un_addr));
	ret = real_recvfrom(s, buf, len, flags, (struct sockaddr *)&un_addr, &un_addrlen);
	if (ret == -1) 
		return ret;

	if (sockaddr_convert_from_un(si, &un_addr, un_addrlen,
				     si->family, from, fromlen) == -1) {
		return -1;
	}

	swrap_dump_packet(si, from, SWRAP_RECVFROM, buf, ret);

	return ret;
}


_PUBLIC_ ssize_t swrap_sendto(int s, const void *buf, size_t len, int flags, const struct sockaddr *to, socklen_t tolen)
{
	struct sockaddr_un un_addr;
	int ret;
	struct socket_info *si = find_socket_info(s);
	int bcast = 0;

	if (!si) {
		return real_sendto(s, buf, len, flags, to, tolen);
	}

	if (si->bound == 0) {
		ret = swrap_auto_bind(si);
		if (ret == -1) return -1;
	}

	ret = sockaddr_convert_to_un(si, to, tolen, &un_addr, 0, &bcast);
	if (ret == -1) return -1;

	if (bcast) {
		struct stat st;
		unsigned int iface;
		unsigned int prt = ntohs(((const struct sockaddr_in *)to)->sin_port);
		char type;

		type = SOCKET_TYPE_CHAR_UDP;

		for(iface=0; iface <= MAX_WRAPPED_INTERFACES; iface++) {
			snprintf(un_addr.sun_path, sizeof(un_addr.sun_path), "%s/"SOCKET_FORMAT, 
				 socket_wrapper_dir(), type, iface, prt);
			if (stat(un_addr.sun_path, &st) != 0) continue;

			/* ignore the any errors in broadcast sends */
			real_sendto(s, buf, len, flags, (struct sockaddr *)&un_addr, sizeof(un_addr));
		}

		swrap_dump_packet(si, to, SWRAP_SENDTO, buf, len);

		return len;
	}

	ret = real_sendto(s, buf, len, flags, (struct sockaddr *)&un_addr, sizeof(un_addr));

	/* to give better errors */
	if (ret == -1 && errno == ENOENT) {
		errno = EHOSTUNREACH;
	}

	if (ret == -1) {
		swrap_dump_packet(si, to, SWRAP_SENDTO, buf, len);
		swrap_dump_packet(si, to, SWRAP_SENDTO_UNREACH, buf, len);
	} else {
		swrap_dump_packet(si, to, SWRAP_SENDTO, buf, ret);
	}

	return ret;
}

_PUBLIC_ int swrap_ioctl(int s, int r, void *p)
{
	int ret;
	struct socket_info *si = find_socket_info(s);
	int value;

	if (!si) {
		return real_ioctl(s, r, p);
	}

	ret = real_ioctl(s, r, p);

	switch (r) {
	case FIONREAD:
		value = *((int *)p);
		if (ret == -1 && errno != EAGAIN && errno != ENOBUFS) {
			swrap_dump_packet(si, NULL, SWRAP_PENDING_RST, NULL, 0);
		} else if (value == 0) { /* END OF FILE */
			swrap_dump_packet(si, NULL, SWRAP_PENDING_RST, NULL, 0);
		}
		break;
	}

	return ret;
}

_PUBLIC_ ssize_t swrap_recv(int s, void *buf, size_t len, int flags)
{
	int ret;
	struct socket_info *si = find_socket_info(s);

	if (!si) {
		return real_recv(s, buf, len, flags);
	}

	ret = real_recv(s, buf, len, flags);
	if (ret == -1 && errno != EAGAIN && errno != ENOBUFS) {
		swrap_dump_packet(si, NULL, SWRAP_RECV_RST, NULL, 0);
	} else if (ret == 0) { /* END OF FILE */
		swrap_dump_packet(si, NULL, SWRAP_RECV_RST, NULL, 0);
	} else {
		swrap_dump_packet(si, NULL, SWRAP_RECV, buf, ret);
	}

	return ret;
}


_PUBLIC_ ssize_t swrap_send(int s, const void *buf, size_t len, int flags)
{
	int ret;
	struct socket_info *si = find_socket_info(s);

	if (!si) {
		return real_send(s, buf, len, flags);
	}

	ret = real_send(s, buf, len, flags);

	if (ret == -1) {
		swrap_dump_packet(si, NULL, SWRAP_SEND, buf, len);
		swrap_dump_packet(si, NULL, SWRAP_SEND_RST, NULL, 0);
	} else {
		swrap_dump_packet(si, NULL, SWRAP_SEND, buf, ret);
	}

	return ret;
}

_PUBLIC_ int swrap_close(int fd)
{
	struct socket_info *si = find_socket_info(fd);
	int ret;

	if (!si) {
		return real_close(fd);
	}

	SWRAP_DLIST_REMOVE(sockets, si);

	if (si->myname && si->peername) {
		swrap_dump_packet(si, NULL, SWRAP_CLOSE_SEND, NULL, 0);
	}

	ret = real_close(fd);

	if (si->myname && si->peername) {
		swrap_dump_packet(si, NULL, SWRAP_CLOSE_RECV, NULL, 0);
		swrap_dump_packet(si, NULL, SWRAP_CLOSE_ACK, NULL, 0);
	}

	if (si->path) free(si->path);
	if (si->myname) free(si->myname);
	if (si->peername) free(si->peername);
	if (si->tmp_path) {
		unlink(si->tmp_path);
		free(si->tmp_path);
	}
	free(si);

	return ret;
}