--- /dev/null
+/*
+ * lib/socket.c Netlink Socket
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation version 2.1
+ * of the License.
+ *
+ * Copyright (c) 2003-2008 Thomas Graf <tgraf@suug.ch>
+ */
+
+/**
+ * @ingroup core
+ * @defgroup socket Socket
+ * @{
+ */
+
+#include <netlink-local.h>
+#include <netlink/netlink.h>
+#include <netlink/utils.h>
+#include <netlink/handlers.h>
+#include <netlink/msg.h>
+#include <netlink/attr.h>
+
+static uint32_t used_ports_map[32];
+
+static uint32_t generate_local_port(void)
+{
+ int i, n;
+ uint32_t pid = getpid() & 0x3FFFFF;
+
+ for (i = 0; i < 32; i++) {
+ if (used_ports_map[i] == 0xFFFFFFFF)
+ continue;
+
+ for (n = 0; n < 32; n++) {
+ if (1UL & (used_ports_map[i] >> n))
+ continue;
+
+ used_ports_map[i] |= (1UL << n);
+ n += (i * 32);
+
+ /* PID_MAX_LIMIT is currently at 2^22, leaving 10 bit
+ * to, i.e. 1024 unique ports per application. */
+ return pid + (n << 22);
+
+ }
+ }
+
+ /* Out of sockets in our own PID namespace, what to do? FIXME */
+ return UINT_MAX;
+}
+
+static void release_local_port(uint32_t port)
+{
+ int nr;
+
+ if (port == UINT_MAX)
+ return;
+
+ nr = port >> 22;
+ used_ports_map[nr / 32] &= ~(1 << nr % 32);
+}
+
+/**
+ * @name Allocation
+ * @{
+ */
+
+static struct nl_sock *__alloc_socket(struct nl_cb *cb)
+{
+ struct nl_sock *sk;
+
+ sk = calloc(1, sizeof(*sk));
+ if (!sk)
+ return NULL;
+
+ sk->s_fd = -1;
+ sk->s_cb = cb;
+ sk->s_local.nl_family = AF_NETLINK;
+ sk->s_peer.nl_family = AF_NETLINK;
+ sk->s_seq_expect = sk->s_seq_next = time(0);
+ sk->s_local.nl_pid = generate_local_port();
+ if (sk->s_local.nl_pid == UINT_MAX) {
+ nl_socket_free(sk);
+ return NULL;
+ }
+
+ return sk;
+}
+
+/**
+ * Allocate new netlink socket
+ *
+ * @return Newly allocated netlink socket or NULL.
+ */
+struct nl_sock *nl_socket_alloc(void)
+{
+ struct nl_cb *cb;
+
+ cb = nl_cb_alloc(NL_CB_DEFAULT);
+ if (!cb)
+ return NULL;
+
+ return __alloc_socket(cb);
+}
+
+/**
+ * Allocate new socket with custom callbacks
+ * @arg cb Callback handler
+ *
+ * The reference to the callback handler is taken into account
+ * automatically, it is released again upon calling nl_socket_free().
+ *
+ *@return Newly allocted socket handle or NULL.
+ */
+struct nl_sock *nl_socket_alloc_cb(struct nl_cb *cb)
+{
+ if (cb == NULL)
+ BUG();
+
+ return __alloc_socket(nl_cb_get(cb));
+}
+
+/**
+ * Free a netlink socket.
+ * @arg sk Netlink socket.
+ */
+void nl_socket_free(struct nl_sock *sk)
+{
+ if (!sk)
+ return;
+
+ if (sk->s_fd >= 0)
+ close(sk->s_fd);
+
+ if (!(sk->s_flags & NL_OWN_PORT))
+ release_local_port(sk->s_local.nl_pid);
+
+ nl_cb_put(sk->s_cb);
+ free(sk);
+}
+
+/** @} */
+
+/**
+ * @name Sequence Numbers
+ * @{
+ */
+
+static int noop_seq_check(struct nl_msg *msg, void *arg)
+{
+ return NL_OK;
+}
+
+
+/**
+ * Disable sequence number checking.
+ * @arg sk Netlink socket.
+ *
+ * Disables checking of sequence numbers on the netlink socket This is
+ * required to allow messages to be processed which were not requested by
+ * a preceding request message, e.g. netlink events.
+ *
+ * @note This function modifies the NL_CB_SEQ_CHECK configuration in
+ * the callback handle associated with the socket.
+ */
+void nl_socket_disable_seq_check(struct nl_sock *sk)
+{
+ nl_cb_set(sk->s_cb, NL_CB_SEQ_CHECK,
+ NL_CB_CUSTOM, noop_seq_check, NULL);
+}
+
+/** @} */
+
+/**
+ * Set local port of socket
+ * @arg sk Netlink socket.
+ * @arg port Local port identifier
+ *
+ * Assigns a local port identifier to the socket. If port is 0
+ * a unique port identifier will be generated automatically.
+ */
+void nl_socket_set_local_port(struct nl_sock *sk, uint32_t port)
+{
+ if (port == 0) {
+ port = generate_local_port();
+ sk->s_flags &= ~NL_OWN_PORT;
+ } else {
+ if (!(sk->s_flags & NL_OWN_PORT))
+ release_local_port(sk->s_local.nl_pid);
+ sk->s_flags |= NL_OWN_PORT;
+ }
+
+ sk->s_local.nl_pid = port;
+}
+
+/** @} */
+
+/**
+ * @name Group Subscriptions
+ * @{
+ */
+
+/**
+ * Join groups
+ * @arg sk Netlink socket
+ * @arg group Group identifier
+ *
+ * Joins the specified groups using the modern socket option which
+ * is available since kernel version 2.6.14. It allows joining an
+ * almost arbitary number of groups without limitation. The list
+ * of groups has to be terminated by 0 (%NFNLGRP_NONE).
+ *
+ * Make sure to use the correct group definitions as the older
+ * bitmask definitions for nl_join_groups() are likely to still
+ * be present for backward compatibility reasons.
+ *
+ * @return 0 on sucess or a negative error code.
+ */
+int nl_socket_add_memberships(struct nl_sock *sk, int group, ...)
+{
+ int err;
+ va_list ap;
+
+ if (sk->s_fd == -1)
+ return -NLE_BAD_SOCK;
+
+ va_start(ap, group);
+
+ while (group != 0) {
+ if (group < 0)
+ return -NLE_INVAL;
+
+ err = setsockopt(sk->s_fd, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP,
+ &group, sizeof(group));
+ if (err < 0)
+ return -nl_syserr2nlerr(errno);
+
+ group = va_arg(ap, int);
+ }
+
+ va_end(ap);
+
+ return 0;
+}
+
+/**
+ * Leave groups
+ * @arg sk Netlink socket
+ * @arg group Group identifier
+ *
+ * Leaves the specified groups using the modern socket option
+ * which is available since kernel version 2.6.14. The list of groups
+ * has to terminated by 0 (%NFNLGRP_NONE).
+ *
+ * @see nl_socket_add_membership
+ * @return 0 on success or a negative error code.
+ */
+int nl_socket_drop_memberships(struct nl_sock *sk, int group, ...)
+{
+ int err;
+ va_list ap;
+
+ if (sk->s_fd == -1)
+ return -NLE_BAD_SOCK;
+
+ va_start(ap, group);
+
+ while (group != 0) {
+ if (group < 0)
+ return -NLE_INVAL;
+
+ err = setsockopt(sk->s_fd, SOL_NETLINK, NETLINK_DROP_MEMBERSHIP,
+ &group, sizeof(group));
+ if (err < 0)
+ return -nl_syserr2nlerr(errno);
+
+ group = va_arg(ap, int);
+ }
+
+ va_end(ap);
+
+ return 0;
+}
+
+
+/** @} */
+
+/**
+ * Set file descriptor of socket to non-blocking state
+ * @arg sk Netlink socket.
+ *
+ * @return 0 on success or a negative error code.
+ */
+int nl_socket_set_nonblocking(struct nl_sock *sk)
+{
+ if (sk->s_fd == -1)
+ return -NLE_BAD_SOCK;
+
+ if (fcntl(sk->s_fd, F_SETFL, O_NONBLOCK) < 0)
+ return -nl_syserr2nlerr(errno);
+
+ return 0;
+}
+
+/** @} */
+
+/**
+ * @name Utilities
+ * @{
+ */
+
+/**
+ * Set socket buffer size of netlink socket.
+ * @arg sk Netlink socket.
+ * @arg rxbuf New receive socket buffer size in bytes.
+ * @arg txbuf New transmit socket buffer size in bytes.
+ *
+ * Sets the socket buffer size of a netlink socket to the specified
+ * values \c rxbuf and \c txbuf. Providing a value of \c 0 assumes a
+ * good default value.
+ *
+ * @note It is not required to call this function prior to nl_connect().
+ * @return 0 on sucess or a negative error code.
+ */
+int nl_socket_set_buffer_size(struct nl_sock *sk, int rxbuf, int txbuf)
+{
+ int err;
+
+ if (rxbuf <= 0)
+ rxbuf = 32768;
+
+ if (txbuf <= 0)
+ txbuf = 32768;
+
+ if (sk->s_fd == -1)
+ return -NLE_BAD_SOCK;
+
+ err = setsockopt(sk->s_fd, SOL_SOCKET, SO_SNDBUF,
+ &txbuf, sizeof(txbuf));
+ if (err < 0)
+ return -nl_syserr2nlerr(errno);
+
+ err = setsockopt(sk->s_fd, SOL_SOCKET, SO_RCVBUF,
+ &rxbuf, sizeof(rxbuf));
+ if (err < 0)
+ return -nl_syserr2nlerr(errno);
+
+ sk->s_flags |= NL_SOCK_BUFSIZE_SET;
+
+ return 0;
+}
+
+/**
+ * Enable/disable credential passing on netlink socket.
+ * @arg sk Netlink socket.
+ * @arg state New state (0 - disabled, 1 - enabled)
+ *
+ * @return 0 on success or a negative error code
+ */
+int nl_socket_set_passcred(struct nl_sock *sk, int state)
+{
+ int err;
+
+ if (sk->s_fd == -1)
+ return -NLE_BAD_SOCK;
+
+ err = setsockopt(sk->s_fd, SOL_SOCKET, SO_PASSCRED,
+ &state, sizeof(state));
+ if (err < 0)
+ return -nl_syserr2nlerr(errno);
+
+ if (state)
+ sk->s_flags |= NL_SOCK_PASSCRED;
+ else
+ sk->s_flags &= ~NL_SOCK_PASSCRED;
+
+ return 0;
+}
+
+/**
+ * Enable/disable receival of additional packet information
+ * @arg sk Netlink socket.
+ * @arg state New state (0 - disabled, 1 - enabled)
+ *
+ * @return 0 on success or a negative error code
+ */
+int nl_socket_recv_pktinfo(struct nl_sock *sk, int state)
+{
+ int err;
+
+ if (sk->s_fd == -1)
+ return -NLE_BAD_SOCK;
+
+ err = setsockopt(sk->s_fd, SOL_NETLINK, NETLINK_PKTINFO,
+ &state, sizeof(state));
+ if (err < 0)
+ return -nl_syserr2nlerr(errno);
+
+ return 0;
+}
+
+/** @} */
+
+/** @} */
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