a63a9ec808
This reverts commit 7097f052d9.
libnl_2 needs to stay in AOSP for now for compatibility with
GPL test builds.
150 lines
3.5 KiB
C
150 lines
3.5 KiB
C
/*
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* Copyright (C) 2011 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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/* NOTICE: This is a clean room re-implementation of libnl */
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#include <malloc.h>
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#include <unistd.h>
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#include <sys/socket.h>
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#include <linux/netlink.h>
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#include "netlink-types.h"
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/* Allocate a new netlink message with the default maximum payload size. */
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struct nl_msg *nlmsg_alloc(void)
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{
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/* Whole page will store nl_msg + nlmsghdr + genlmsghdr + payload */
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const int page_sz = getpagesize();
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struct nl_msg *nm;
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struct nlmsghdr *nlh;
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/* Netlink message */
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nm = (struct nl_msg *) malloc(page_sz);
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if (!nm)
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goto fail;
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/* Netlink message header pointer */
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nlh = (struct nlmsghdr *) ((char *) nm + sizeof(struct nl_msg));
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/* Initialize */
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memset(nm, 0, page_sz);
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nm->nm_size = page_sz;
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nm->nm_src.nl_family = AF_NETLINK;
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nm->nm_src.nl_pid = getpid();
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nm->nm_dst.nl_family = AF_NETLINK;
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nm->nm_dst.nl_pid = 0; /* Kernel */
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/* Initialize and add to netlink message */
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nlh->nlmsg_len = NLMSG_HDRLEN;
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nm->nm_nlh = nlh;
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/* Add to reference count and return nl_msg */
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nlmsg_get(nm);
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return nm;
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fail:
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return NULL;
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}
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/* Return pointer to message payload. */
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void *nlmsg_data(const struct nlmsghdr *nlh)
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{
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return (char *) nlh + NLMSG_HDRLEN;
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}
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/* Add reference count to nl_msg */
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void nlmsg_get(struct nl_msg *nm)
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{
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nm->nm_refcnt++;
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}
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/* Release a reference from an netlink message. */
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void nlmsg_free(struct nl_msg *nm)
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{
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if (nm) {
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nm->nm_refcnt--;
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if (nm->nm_refcnt <= 0)
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free(nm);
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}
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}
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/* Return actual netlink message. */
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struct nlmsghdr *nlmsg_hdr(struct nl_msg *n)
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{
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return n->nm_nlh;
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}
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/* Return head of attributes data / payload section */
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struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh, int hdrlen)
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{
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unsigned char *data = nlmsg_data(nlh);
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return (struct nlattr *)(data + NLMSG_ALIGN(hdrlen));
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}
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/* Returns pointer to end of netlink message */
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void *nlmsg_tail(const struct nlmsghdr *nlh)
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{
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return (void *)((char *)nlh + NLMSG_ALIGN(nlh->nlmsg_len));
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}
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/* Next netlink message in message stream */
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struct nlmsghdr *nlmsg_next(struct nlmsghdr *nlh, int *remaining)
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{
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struct nlmsghdr *next_nlh = NULL;
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int len = nlmsg_len(nlh);
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len = NLMSG_ALIGN(len);
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if (*remaining > 0 &&
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len <= *remaining &&
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len >= (int) sizeof(struct nlmsghdr)) {
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next_nlh = (struct nlmsghdr *)((char *)nlh + len);
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*remaining -= len;
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}
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return next_nlh;
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}
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int nlmsg_datalen(const struct nlmsghdr *nlh)
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{
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return nlh->nlmsg_len - NLMSG_HDRLEN;
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}
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/* Length of attributes data */
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int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
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{
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return nlmsg_datalen(nlh) - NLMSG_ALIGN(hdrlen);
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}
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/* Length of netlink message */
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int nlmsg_len(const struct nlmsghdr *nlh)
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{
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return nlh->nlmsg_len;
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}
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/* Check if the netlink message fits into the remaining bytes */
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int nlmsg_ok(const struct nlmsghdr *nlh, int rem)
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{
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return rem >= (int)sizeof(struct nlmsghdr) &&
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rem >= nlmsg_len(nlh) &&
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nlmsg_len(nlh) >= (int) sizeof(struct nlmsghdr) &&
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nlmsg_len(nlh) <= (rem);
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}
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int nlmsg_padlen(int payload)
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{
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return NLMSG_ALIGN(payload) - payload;
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}
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