From 716ca530e1c4515d8683c9d5be3d56b301758b66 Mon Sep 17 00:00:00 2001 From: James <> Date: Wed, 4 Nov 2015 11:49:21 +0000 Subject: trunk-47381 --- package/libs/libnl-tiny/src/socket.c | 406 +++++++++++++++++++++++++++++++++++ 1 file changed, 406 insertions(+) create mode 100644 package/libs/libnl-tiny/src/socket.c (limited to 'package/libs/libnl-tiny/src/socket.c') diff --git a/package/libs/libnl-tiny/src/socket.c b/package/libs/libnl-tiny/src/socket.c new file mode 100644 index 0000000..1429825 --- /dev/null +++ b/package/libs/libnl-tiny/src/socket.c @@ -0,0 +1,406 @@ +/* + * 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 + */ + +/** + * @ingroup core + * @defgroup socket Socket + * @{ + */ + +#include +#include +#include +#include +#include +#include + +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; +} + +/** @} */ + +/** @} */ -- cgit v1.2.3