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/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/* NOTICE: This is a clean room re-implementation of libnl */
#include <errno.h>
#include "netlink/netlink.h"
#include "netlink/msg.h"
#include "netlink/attr.h"
#include "netlink-types.h"
/* Return payload of string attribute. */
char *nla_get_string(struct nlattr *nla)
{
return (char *) nla_data(nla);
}
/* Return payload of 16 bit integer attribute. */
uint16_t nla_get_u16(struct nlattr *nla)
{
return *((uint16_t *) nla_data(nla));
}
/* Return payload of 32 bit integer attribute. */
uint32_t nla_get_u32(struct nlattr *nla)
{
return *((uint32_t *) nla_data(nla));
}
/* Return value of 8 bit integer attribute. */
uint8_t nla_get_u8(struct nlattr *nla)
{
return *((uint8_t *) nla_data(nla));
}
/* Return payload of uint64_t attribute. */
uint64_t nla_get_u64(struct nlattr *nla)
{
uint64_t tmp;
nla_memcpy(&tmp, nla, sizeof(tmp));
return tmp;
}
/* Head of payload */
void *nla_data(const struct nlattr *nla)
{
return (void *) ((char *) nla + NLA_HDRLEN);
}
/* Return length of the payload . */
int nla_len(const struct nlattr *nla)
{
return nla->nla_len - NLA_HDRLEN;
}
int nla_padlen(int payload)
{
return NLA_ALIGN(payload) - payload;
}
/* Start a new level of nested attributes. */
struct nlattr *nla_nest_start(struct nl_msg *msg, int attrtype)
{
struct nlattr *start = (struct nlattr *)nlmsg_tail(msg->nm_nlh);
int rc;
rc = nla_put(msg, attrtype, 0, NULL);
if (rc < 0)
return NULL;
return start;
}
/* Finalize nesting of attributes. */
int nla_nest_end(struct nl_msg *msg, struct nlattr *start)
{
/* Set attribute size */
start->nla_len = (unsigned char *)nlmsg_tail(nlmsg_hdr(msg)) -
(unsigned char *)start;
return 0;
}
/* Return next attribute in a stream of attributes. */
struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
{
struct nlattr *next_nla = NULL;
if (nla->nla_len >= sizeof(struct nlattr) &&
nla->nla_len <= *remaining){
next_nla = (struct nlattr *) \
((char *) nla + NLA_ALIGN(nla->nla_len));
*remaining = *remaining - NLA_ALIGN(nla->nla_len);
}
return next_nla;
}
/* Check if the attribute header and payload can be accessed safely. */
int nla_ok(const struct nlattr *nla, int remaining)
{
return remaining > 0 &&
nla->nla_len >= sizeof(struct nlattr) &&
sizeof(struct nlattr) <= (unsigned int) remaining &&
nla->nla_len <= remaining;
}
/* Create attribute index based on a stream of attributes. */
/* NOTE: Policy not used ! */
int nla_parse(struct nlattr *tb[], int maxtype, struct nlattr *head,
int len, struct nla_policy *policy)
{
struct nlattr *pos;
int rem;
/* First clear table */
memset(tb, 0, (maxtype + 1) * sizeof(struct nlattr *));
nla_for_each_attr(pos, head, len, rem) {
int type = nla_type(pos);
if ((type <= maxtype) && (type != 0))
tb[type] = pos;
}
return 0;
}
/* Create attribute index based on nested attribute. */
int nla_parse_nested(struct nlattr *tb[], int maxtype,
struct nlattr *nla, struct nla_policy *policy)
{
return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy);
}
/* Add a unspecific attribute to netlink message. */
int nla_put(struct nl_msg *msg, int attrtype, int datalen, const void *data)
{
struct nlattr *nla;
/* Reserve space and init nla header */
nla = nla_reserve(msg, attrtype, datalen);
if (nla) {
memcpy(nla_data(nla), data, datalen);
return 0;
}
return -EINVAL;
}
/* Add nested attributes to netlink message. */
/* Takes the attributes found in the nested message and appends them
* to the message msg nested in a container of the type attrtype. The
* nested message may not have a family specific header */
int nla_put_nested(struct nl_msg *msg, int attrtype, struct nl_msg *nested)
{
int rc;
rc = nla_put(msg, attrtype, nlmsg_attrlen(nlmsg_hdr(nested), 0),
nlmsg_attrdata(nlmsg_hdr(nested), 0));
return rc;
}
/* Return type of the attribute. */
int nla_type(const struct nlattr *nla)
{
return (int)nla->nla_type & NLA_TYPE_MASK;
}
/* Reserves room for an attribute in specified netlink message and fills
* in the attribute header (type,length). Return NULL if insufficient space */
struct nlattr *nla_reserve(struct nl_msg *msg, int attrtype, int data_len)
{
struct nlattr *nla;
const unsigned int NEW_SIZE = NLMSG_ALIGN(msg->nm_nlh->nlmsg_len) +
NLA_ALIGN(NLA_HDRLEN + data_len);
/* Check enough space for attribute */
if (NEW_SIZE > msg->nm_size)
return NULL;
nla = (struct nlattr *)nlmsg_tail(msg->nm_nlh);
nla->nla_type = attrtype;
nla->nla_len = NLA_HDRLEN + data_len;
memset((unsigned char *)nla + nla->nla_len, 0, nla_padlen(data_len));
msg->nm_nlh->nlmsg_len = NEW_SIZE;
return nla;
}
/* Copy attribute payload to another memory area. */
int nla_memcpy(void *dest, struct nlattr *src, int count)
{
if (!src || !dest)
return 0;
if (count > nla_len(src))
count = nla_len(src);
memcpy(dest, nla_data(src), count);
return count;
}
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