/*
- * Copyright (C) 2005-2011 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2005 Andre Noll <maan@tuebingen.mpg.de>
*
* Licensed under the GPL v2. For licencing details see COPYING.
*/
*/
#define _GNU_SOURCE
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <sys/un.h>
+#include <sys/types.h>
+#include <sys/socket.h>
#include <netdb.h>
/* At least NetBSD needs these. */
* \param netmask Value of the netmask part in \a cidr or the
* default of 32 if not specified.
*
- * \return Pointer to \a addr if succesful, NULL on error.
+ * \return Pointer to \a addr if successful, NULL on error.
* \sa RFC 4632
*/
char *parse_cidr(const char *cidr,
* \param hostlen The maximum length of \a host.
* \param port To return the port number (if any) of \a url.
*
- * \return Pointer to \a host, or NULL if failed.
- * If NULL is returned, \a host and \a portnum are undefined. If no
- * port number was present in \a url, \a portnum is set to -1.
+ * \return Pointer to \a host, or \p NULL if failed. If \p NULL is returned,
+ * \a host and \a port are undefined. If no port number was present in \a url,
+ * \a port is set to -1.
*
* \sa RFC 3986, 3.2.2/3.2.3
*/
if (*o++ != ']' || (*o != '\0' && *o != ':'))
goto failed;
} else {
- for (; (*c = *o == ':'? '\0' : *o); c++, o++)
- if (c == end)
+ for (; (*c = *o == ':'? '\0' : *o); c++, o++) {
+ if (c == end && o[1])
goto failed;
+ }
}
if (*o == ':')
if (para_atoi32(++o, port) < 0 ||
*port < 0 || *port > 0xffff)
goto failed;
-
if (host_string_ok(host))
return host;
failed:
struct servent *se = getservbyport(htons(port), transport);
if (se == NULL)
- snprintf(service, sizeof(service), "%u", port);
+ snprintf(service, sizeof(service), "%d", port);
else
snprintf(service, sizeof(service), "%s", se->s_name);
}
struct list_head sockopts;
};
+/**
+ * Allocate and initialize a flowopt queue.
+ *
+ * \return A new structure to be passed to \ref flowopt_add(). It is
+ * automatically deallocated in \ref makesock().
+ */
struct flowopts *flowopt_new(void)
{
struct flowopts *new = para_malloc(sizeof(*new));
list_add_tail(&new->node, &fo->sockopts);
}
-void flowopt_add_bool(struct flowopts *fo, int lev, int opt,
- const char *optname, bool on_or_off)
-{
- int on = on_or_off; /* kernel takes 'int' */
-
- flowopt_add(fo, lev, opt, optname, &on, sizeof(on));
-}
-
/** Set the entire bunch of pre-connection options at once. */
static void flowopt_setopts(int sockfd, struct flowopts *fo)
{
}
}
-static void flowopt_cleanup(struct flowopts *fo)
+/**
+ * Deallocate all resources of a flowopts structure.
+ *
+ * \param fo A pointer as returned from flowopt_new().
+ *
+ * It's OK to pass \p NULL here in which case the function does nothing.
+ */
+void flowopt_cleanup(struct flowopts *fo)
{
struct pre_conn_opt *cur, *next;
}
/**
- * Resolve IPv4/IPv6 address and create a ready-to-use active or passive socket.
+ * Resolve an IPv4/IPv6 address.
*
* \param l4type The layer-4 type (\p IPPROTO_xxx).
- * \param passive Whether this is a passive (1) or active (0) socket.
+ * \param passive Whether \p AI_PASSIVE should be included as hint.
* \param host Remote or local hostname or IPv/6 address string.
- * \param port_number Decimal port number.
- * \param fo Socket options to be set before making the connection.
+ * \param port_number Used to set the port in each returned address structure.
+ * \param result addrinfo structures are returned here.
*
- * This creates a ready-made IPv4/v6 socket structure after looking up the
- * necessary parameters. The interpretation of \a host depends on the value of
- * \a passive:
- * - on a passive socket host is interpreted as an interface IPv4/6 address
- * (can be left NULL);
- * - on an active socket, \a host is the peer DNS name or IPv4/6 address
- * to connect to;
- * - \a port_number is in either case the numeric port number (not service
- * string).
- *
- * Furthermore, bind(2) is called on passive sockets, and connect(2) on active
- * sockets. The algorithm tries all possible address combinations until it
- * succeeds. If \a fo is supplied, options are set and cleanup is performed.
- *
- * \return This function returns 1 on success and \a -E_ADDRESS_LOOKUP when no
- * matching connection could be set up (with details in the error log).
- *
- * \sa ipv6(7), getaddrinfo(3), bind(2), connect(2).
+ * The interpretation of \a host depends on the value of \a passive. On a
+ * passive socket host is interpreted as an interface IPv4/6 address (can be
+ * left NULL). On an active socket, \a host is the peer DNS name or IPv4/6
+ * address to connect to.
+ *
+ * \return Standard.
+ *
+ * \sa getaddrinfo(3).
*/
-int makesock(unsigned l4type, bool passive,
- const char *host, uint16_t port_number,
- struct flowopts *fo)
+int lookup_address(unsigned l4type, bool passive, const char *host,
+ int port_number, struct addrinfo **result)
{
- struct addrinfo *local = NULL, *src = NULL, *remote = NULL,
- *dst = NULL, hints;
- unsigned int l3type = AF_UNSPEC;
- int rc, on = 1, sockfd = -1,
- socktype = sock_type(l4type);
+ int ret;
char port[6]; /* port number has at most 5 digits */
+ struct addrinfo *addr = NULL, hints;
- sprintf(port, "%u", port_number);
+ *result = NULL;
+ sprintf(port, "%u", port_number & 0xffff);
/* Set up address hint structure */
memset(&hints, 0, sizeof(hints));
- hints.ai_family = l3type;
- hints.ai_socktype = socktype;
- /*
+ hints.ai_family = AF_UNSPEC;
+ hints.ai_socktype = sock_type(l4type);
+ /*
* getaddrinfo does not support SOCK_DCCP, so for the sake of lookup
* (and only then) pretend to be UDP.
*/
if (l4type == IPPROTO_DCCP)
hints.ai_socktype = SOCK_DGRAM;
-
/* only use addresses available on the host */
hints.ai_flags = AI_ADDRCONFIG;
- if (l3type == AF_INET6)
- /* use v4-mapped-v6 if no v6 addresses found */
- hints.ai_flags |= AI_V4MAPPED | AI_ALL;
-
if (passive && host == NULL)
hints.ai_flags |= AI_PASSIVE;
-
/* Obtain local/remote address information */
- if ((rc = getaddrinfo(host, port, &hints, passive ? &local : &remote))) {
- PARA_ERROR_LOG("can not resolve %s address %s#%s: %s.\n",
- layer4_name(l4type),
- host? host : (passive? "[loopback]" : "[localhost]"),
- port, gai_strerror(rc));
- rc = -E_ADDRESS_LOOKUP;
- goto out;
+ ret = getaddrinfo(host, port, &hints, &addr);
+ if (ret != 0) {
+ PARA_ERROR_LOG("can not resolve %s address %s#%s: %s\n",
+ layer4_name(l4type),
+ host? host : (passive? "[loopback]" : "[localhost]"),
+ port, gai_strerror(ret));
+ return -E_ADDRESS_LOOKUP;
}
+ *result = addr;
+ return 1;
+}
- /* Iterate over all src/dst combination, exhausting dst first */
- for (src = local, dst = remote; src != NULL || dst != NULL; /* no op */ ) {
- if (src && dst && src->ai_family == AF_INET
- && dst->ai_family == AF_INET6)
- goto get_next_dst; /* v4 -> v6 is not possible */
-
- sockfd = socket(src ? src->ai_family : dst->ai_family,
- socktype, l4type);
- if (sockfd < 0)
- goto get_next_dst;
+/**
+ * Create an active or passive socket.
+ *
+ * \param l4type \p IPPROTO_TCP, \p IPPROTO_UDP, or \p IPPROTO_DCCP.
+ * \param passive Whether to call bind(2) or connect(2).
+ * \param ai Address information as obtained from \ref lookup_address().
+ * \param fo Socket options to be set before making the connection.
+ *
+ * bind(2) is called on passive sockets, and connect(2) on active sockets. The
+ * algorithm tries all possible address combinations until it succeeds. If \a
+ * fo is supplied, options are set but cleanup must be performed in the caller.
+ *
+ * \return File descriptor on success, \p E_MAKESOCK on errors.
+ *
+ * \sa \ref lookup_address(), \ref makesock(), ip(7), ipv6(7), bind(2),
+ * connect(2).
+ */
+int makesock_addrinfo(unsigned l4type, bool passive, struct addrinfo *ai,
+ struct flowopts *fo)
+{
+ int ret = -E_MAKESOCK, on = 1;
+ for (; ai; ai = ai->ai_next) {
+ int fd;
+ ret = socket(ai->ai_family, sock_type(l4type), l4type);
+ if (ret < 0)
+ continue;
+ fd = ret;
+ flowopt_setopts(fd, fo);
+ if (!passive) {
+ if (connect(fd, ai->ai_addr, ai->ai_addrlen) == 0)
+ return fd;
+ close(fd);
+ continue;
+ }
/*
* Reuse the address on passive sockets to avoid failure on
* restart (protocols using listen()) and when creating
* multiple listener instances (UDP multicast).
*/
- if (passive && setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
- &on, sizeof(on)) == -1) {
- rc = errno;
- close(sockfd);
- PARA_ERROR_LOG("can not set SO_REUSEADDR: %s\n",
- strerror(rc));
- rc = -ERRNO_TO_PARA_ERROR(rc);
- break;
- }
- flowopt_setopts(sockfd, fo);
-
- if (src) {
- if (bind(sockfd, src->ai_addr, src->ai_addrlen) < 0) {
- close(sockfd);
- goto get_next_src;
- }
- if (!dst) /* bind-only completed successfully */
- break;
+ if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on,
+ sizeof(on)) == -1) {
+ close(fd);
+ continue;
}
-
- if (dst && connect(sockfd, dst->ai_addr, dst->ai_addrlen) == 0)
- break; /* connection completed successfully */
- close(sockfd);
-get_next_dst:
- if (dst && (dst = dst->ai_next))
+ if (bind(fd, ai->ai_addr, ai->ai_addrlen) < 0) {
+ close(fd);
continue;
-get_next_src:
- if (src && (src = src->ai_next)) /* restart inner loop */
- dst = remote;
+ }
+ return fd;
}
-out:
- if (local)
- freeaddrinfo(local);
- if (remote)
- freeaddrinfo(remote);
- flowopt_cleanup(fo);
-
- if (src == NULL && dst == NULL) {
- if (rc >= 0)
- rc = -E_MAKESOCK;
- PARA_ERROR_LOG("can not create %s socket %s#%s.\n",
- layer4_name(l4type), host? host : (passive?
- "[loopback]" : "[localhost]"), port);
- return rc;
+ return -E_MAKESOCK;
+}
+
+/**
+ * Resolve IPv4/IPv6 address and create a ready-to-use active or passive socket.
+ *
+ * \param l4type The layer-4 type (\p IPPROTO_xxx).
+ * \param passive Whether this is a passive or active socket.
+ * \param host Passed to \ref lookup_address().
+ * \param port_number Passed to \ref lookup_address().
+ * \param fo Passed to \ref makesock_addrinfo().
+ *
+ * This creates a ready-made IPv4/v6 socket structure after looking up the
+ * necessary parameters. The function first calls \ref lookup_address() and
+ * passes the address information to makesock_addrinfo() to create and
+ * initialize the socket.
+ *
+ * \return The newly created file descriptor on success, a negative error code
+ * on failure.
+ *
+ * \sa \ref lookup_address(), \ref makesock_addrinfo().
+ */
+int makesock(unsigned l4type, bool passive, const char *host, uint16_t port_number,
+ struct flowopts *fo)
+{
+ struct addrinfo *ai;
+ int ret = lookup_address(l4type, passive, host, port_number, &ai);
+
+ if (ret >= 0)
+ ret = makesock_addrinfo(l4type, passive, ai, fo);
+ if (ai)
+ freeaddrinfo(ai);
+ if (ret < 0) {
+ PARA_ERROR_LOG("can not create %s socket %s#%d.\n",
+ layer4_name(l4type), host? host : (passive?
+ "[loopback]" : "[localhost]"), port_number);
}
- return sockfd;
+ return ret;
}
/**
}
/**
- * Maximum transport-layer message size (MMS_S) as per RFC 1122, 3.3.3
- * Socket must be connected.
+ * Get the maximum transport-layer message size (MMS_S).
+ *
+ * \param sockfd The socket file descriptor.
+ *
+ * The socket must be connected. See RFC 1122, 3.3.3. If the protocol family
+ * could not be determined, \p AF_INET is assumed.
+ *
+ * \return The maximum message size of the address family type.
*/
int generic_max_transport_msg_size(int sockfd)
{
}
/**
- * Look up the local or remote side of a connected socket structure.
+ * Look up the remote side of a connected socket structure.
*
* \param fd The socket descriptor of the connected socket.
- * \param getname Either \p getsockname() for local, or \p getpeername() for
- * remote side.
*
* \return A static character string identifying hostname and port of the
* chosen side in numeric host:port format.
* \sa getsockname(2), getpeername(2), parse_url(), getnameinfo(3),
* services(5), nsswitch.conf(5).
*/
-static char *__get_sock_name(int fd, int (*getname)(int, struct sockaddr*,
- socklen_t *))
+char *remote_name(int fd)
{
struct sockaddr_storage ss;
const struct sockaddr *sa;
static char output[sizeof(hbuf) + sizeof(sbuf) + 4];
int ret;
- if (getname(fd, (struct sockaddr *)&ss, &sslen) < 0) {
+ if (getpeername(fd, (struct sockaddr *)&ss, &sslen) < 0) {
PARA_ERROR_LOG("can not determine address from fd %d: %s\n",
fd, strerror(errno));
snprintf(output, sizeof(output), "(unknown)");
return output;
}
-/**
- * Look up the local side of a connected socket structure.
- *
- * \param sockfd The file descriptor of the socket.
- *
- * \return A pointer to a static buffer containing hostname an port. This
- * buffer must not be freed by the caller.
- *
- * \sa remote_name().
- */
-char *local_name(int sockfd)
-{
- return __get_sock_name(sockfd, getsockname);
-}
-
-/**
- * Look up the remote side of a connected socket structure.
- *
- * \param sockfd The file descriptor of the socket.
- *
- * \return Analogous to the return value of \ref local_name() but for the
- * remote side.
- *
- * \sa local_name().
- */
-char *remote_name(int sockfd)
-{
- return __get_sock_name(sockfd, getpeername);
-}
-
/**
* Extract IPv4 or IPv6-mapped-IPv4 address from sockaddr_storage.
- * \param ss Container of IPv4/6 address
- * \return Extracted IPv4 address (different from 0) or 0 if unsuccessful.
*
- * \sa RFC 3493
+ * \param ss Container of IPv4/6 address.
+ * \param ia Extracted IPv4 address (different from 0) or 0 if unsuccessful.
+ *
+ * \sa RFC 3493.
*/
-struct in_addr extract_v4_addr(const struct sockaddr_storage *ss)
+void extract_v4_addr(const struct sockaddr_storage *ss, struct in_addr *ia)
{
- struct in_addr ia = {.s_addr = 0};
const struct sockaddr *sa = normalize_ip_address(ss);
+ memset(ia, 0, sizeof(*ia));
if (sa->sa_family == AF_INET)
- ia = ((struct sockaddr_in *)sa)->sin_addr;
- return ia;
-}
-
-/**
- * Send a binary buffer.
- *
- * \param fd The file descriptor.
- * \param buf The buffer to be sent.
- * \param len The length of \a buf.
- *
- * Send out the buffer and try to resend the remaining part in case of short
- * writes.
- *
- * \return Standard.
- */
-int send_bin_buffer(int fd, const char *buf, size_t len)
-{
- if (!len)
- PARA_CRIT_LOG("len == 0\n");
- return write_all(fd, buf, &len);
+ *ia = ((struct sockaddr_in *)sa)->sin_addr;
}
/**
- * Send a \p NULL-terminated buffer.
- *
- * \param fd The file descriptor.
- * \param buf The null-terminated buffer to be send.
+ * Compare the address part of IPv4/6 addresses.
*
- * This is equivalent to send_bin_buffer(fd, buf, strlen(buf)).
+ * \param sa1 First address.
+ * \param sa2 Second address.
*
- * \return Standard.
+ * \return True iff the IP address of \a sa1 and \a sa2 match.
*/
-int send_buffer(int fd, const char *buf)
+bool sockaddr_equal(const struct sockaddr *sa1, const struct sockaddr *sa2)
{
- return send_bin_buffer(fd, buf, strlen(buf));
-}
-
-/**
- * Send a buffer given by a format string.
- *
- * \param fd The file descriptor.
- * \param fmt A format string.
- *
- * \return Standard.
- */
-__printf_2_3 int send_va_buffer(int fd, const char *fmt, ...)
-{
- char *msg;
- int ret;
-
- PARA_VSPRINTF(fmt, msg);
- ret = send_buffer(fd, msg);
- free(msg);
- return ret;
+ if (!sa1 || !sa2)
+ return false;
+ if (sa1->sa_family != sa2->sa_family)
+ return false;
+ if (sa1->sa_family == AF_INET) {
+ struct sockaddr_in *a1 = (typeof(a1))sa1,
+ *a2 = (typeof (a2))sa2;
+ return a1->sin_addr.s_addr == a2->sin_addr.s_addr;
+ } else if (sa1->sa_family == AF_INET6) {
+ struct sockaddr_in6 *a1 = (typeof(a1))sa1,
+ *a2 = (typeof (a2))sa2;
+ return !memcmp(a1, a2, sizeof(*a1));
+ } else
+ return false;
}
/**
* \return Positive on success, \p -E_NAME_TOO_LONG if \a name is longer
* than \p UNIX_PATH_MAX.
*/
-static int init_unix_addr(struct sockaddr_un *u, const char *name)
+static int init_unix_addr(struct sockaddr_un *u, const char *name,
+ bool abstract)
{
- if (strlen(name) >= UNIX_PATH_MAX)
+ if (strlen(name) + abstract >= UNIX_PATH_MAX)
return -E_NAME_TOO_LONG;
memset(u->sun_path, 0, UNIX_PATH_MAX);
u->sun_family = PF_UNIX;
- strcpy(u->sun_path, name);
+ strcpy(u->sun_path + abstract, name);
return 1;
}
/**
- * Prepare, create, and bind a socket for local communication.
+ * Create a socket for local communication and listen on it.
*
* \param name The socket pathname.
- * \param unix_addr Pointer to the \p AF_UNIX socket structure.
- * \param mode The desired mode of the socket.
+ * \param mode The desired permissions of the socket.
+ *
+ * This function creates a passive local socket for sequenced, reliable,
+ * two-way, connection-based byte streams. The socket file descriptor is set to
+ * nonblocking mode and listen(2) is called to prepare the socket for
+ * accepting incoming connection requests.
*
- * This function creates a local socket for sequenced, reliable,
- * two-way, connection-based byte streams.
+ * If mode is zero, an abstract socket (a non-portable Linux extension) is
+ * created. In this case the socket name has no connection with filesystem
+ * pathnames.
*
- * \return The file descriptor, on success, negative on errors.
+ * \return The file descriptor on success, negative error code on failure.
*
- * \sa socket(2)
- * \sa bind(2)
- * \sa chmod(2)
+ * \sa socket(2), \sa bind(2), \sa chmod(2), listen(2), unix(7).
*/
-int create_local_socket(const char *name, struct sockaddr_un *unix_addr,
- mode_t mode)
+int create_local_socket(const char *name, mode_t mode)
{
+ struct sockaddr_un unix_addr;
int fd, ret;
+ bool abstract = mode == 0;
- ret = init_unix_addr(unix_addr, name);
+ ret = init_unix_addr(&unix_addr, name, abstract);
if (ret < 0)
return ret;
ret = socket(PF_UNIX, SOCK_STREAM, 0);
if (ret < 0)
return -ERRNO_TO_PARA_ERROR(errno);
fd = ret;
- ret = bind(fd, (struct sockaddr *) unix_addr, UNIX_PATH_MAX);
+ ret = mark_fd_nonblocking(fd);
+ if (ret < 0)
+ goto err;
+ ret = bind(fd, (struct sockaddr *)&unix_addr, sizeof(unix_addr));
if (ret < 0) {
ret = -ERRNO_TO_PARA_ERROR(errno);
goto err;
}
- ret = -E_CHMOD;
- if (chmod(name, mode) < 0)
+ if (!abstract) {
+ ret = -E_CHMOD;
+ if (chmod(name, mode) < 0)
+ goto err;
+ }
+ if (listen(fd , 5) < 0) {
+ ret = -ERRNO_TO_PARA_ERROR(errno);
goto err;
+ }
return fd;
err:
close(fd);
int fd, ret;
PARA_DEBUG_LOG("connecting to %s\n", name);
- ret = init_unix_addr(&unix_addr, name);
- if (ret < 0)
- return ret;
fd = socket(PF_UNIX, SOCK_STREAM, 0);
if (fd < 0)
return -ERRNO_TO_PARA_ERROR(errno);
- if (connect(fd, (struct sockaddr *)&unix_addr, sizeof(unix_addr)) == -1) {
- ret = -ERRNO_TO_PARA_ERROR(errno);
+ /* first try (linux-only) abstract socket */
+ ret = init_unix_addr(&unix_addr, name, true);
+ if (ret < 0)
goto err;
- }
- return fd;
+ if (connect(fd, (struct sockaddr *)&unix_addr, sizeof(unix_addr)) != -1)
+ return fd;
+ /* next try pathname socket */
+ ret = init_unix_addr(&unix_addr, name, false);
+ if (ret < 0)
+ goto err;
+ if (connect(fd, (struct sockaddr *)&unix_addr, sizeof(unix_addr)) != -1)
+ return fd;
+ ret = -ERRNO_TO_PARA_ERROR(errno);
err:
close(fd);
return ret;
#ifndef HAVE_UCRED
ssize_t send_cred_buffer(int sock, char *buf)
{
- return send_buffer(sock, buf);
+ return write_buffer(sock, buf);
}
int recv_cred_buffer(int fd, char *buf, size_t size)
{
return recv_buffer(fd, buf, size) > 0? 1 : -E_RECVMSG;
}
#else /* HAVE_UCRED */
+
/**
- * Send \p NULL-terminated buffer and Unix credentials of the current process.
+ * Send a buffer and the credentials of the current process to a socket.
*
- * \param sock The socket file descriptor.
- * \param buf The buffer to be sent.
+ * \param sock The file descriptor of the sending socket.
+ * \param buf The zero-terminated buffer to send.
*
- * \return On success, this call returns the number of characters sent. On
- * error, \p -E_SENDMSG is returned.
+ * \return On success, this call returns the number of bytes sent. On errors,
+ * \p -E_SENDMSG is returned.
*
- * \sa sendmsg(2), okir's Black Hats Manual.
+ * \sa \ref recv_cred_buffer, sendmsg(2), socket(7), unix(7), okir's Black Hats
+ * Manual.
*/
ssize_t send_cred_buffer(int sock, char *buf)
{
/* Response data */
iov.iov_base = buf;
- iov.iov_len = strlen(buf);
+ iov.iov_len = strlen(buf);
c.pid = getpid();
c.uid = getuid();
c.gid = getgid();
*(struct ucred *)CMSG_DATA(cmsg) = c;
msg.msg_controllen = cmsg->cmsg_len;
ret = sendmsg(sock, &msg, 0);
- if (ret < 0)
+ if (ret < 0)
ret = -E_SENDMSG;
return ret;
}
/**
* Receive a buffer and the Unix credentials of the sending process.
*
- * \param fd the socket file descriptor.
- * \param buf the buffer to store the message.
- * \param size the size of \a buffer.
+ * \param fd The file descriptor of the receiving socket.
+ * \param buf The buffer to store the received message.
+ * \param size The length of \a buf in bytes.
*
- * \return negative on errors, the user id on success.
+ * \return Negative on errors, the user id of the sending process on success.
*
- * \sa recvmsg(2), okir's Black Hats Manual.
+ * \sa \ref send_cred_buffer and the references given there.
*/
int recv_cred_buffer(int fd, char *buf, size_t size)
{
} else
if (cmsg->cmsg_level == SOL_SOCKET
&& cmsg->cmsg_type == SCM_RIGHTS) {
- dispose_fds((int *) CMSG_DATA(cmsg),
+ dispose_fds((int *)CMSG_DATA(cmsg),
(cmsg->cmsg_len - CMSG_LEN(0))
/ sizeof(int));
}