+++ /dev/null
-/*
- * lib/attr.c Netlink Attributes
- *
- * 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) 2003-2006 Thomas Graf <tgraf@suug.ch>
- */
-
-#include <netlink-local.h>
-#include <netlink/netlink.h>
-#include <netlink/utils.h>
-#include <netlink/addr.h>
-#include <netlink/attr.h>
-#include <netlink/msg.h>
-#include <linux/socket.h>
-
-/**
- * @ingroup nl
- * @defgroup attr Attributes
- * Netlink Attributes Construction/Parsing Interface
- * @par 0) Introduction
- * Netlink attributes are chained together following each other:
- * @code
- * <------- nla_total_size(payload) ------->
- * <---- nla_attr_size(payload) ----->
- * +----------+- - -+- - - - - - - - - +- - -+-------- - -
- * | Header | Pad | Payload | Pad | Header
- * +----------+- - -+- - - - - - - - - +- - -+-------- - -
- * <- nla_len(nla) -> ^
- * nla_data(nla)----^ |
- * nla_next(nla)-----------------------------'
- * @endcode
- *
- * @par
- * The attribute header and payload must be aligned properly:
- * @code
- * <------- NLA_HDRLEN ------> <-- NLA_ALIGN(payload)-->
- * +---------------------+- - -+- - - - - - - - - -+- - -+
- * | Header | Pad | Payload | Pad |
- * | (struct nlattr) | ing | | ing |
- * +---------------------+- - -+- - - - - - - - - -+- - -+
- * <-------------- nlattr->nla_len -------------->
- * @endcode
- *
- * @par Nested TLVs:
- * Nested TLVs are an array of TLVs nested into another TLV. This can be useful
- * to allow subsystems to have their own formatting rules without the need to
- * make the underlying layer be aware of it. It can also be useful to transfer
- * arrays, lists and flattened trees.
- * \code
- * <-------------------- NLA_ALIGN(...) ------------------->
- * +---------------+- - - - - - - - - - - - - - - - - -+- - -+
- * | |+---------+---------+- - -+-------+| |
- * | TLV Header || TLV 1 | TLV 2 | | TLV n || Pad |
- * | |+---------+---------+- - -+-------+| |
- * +---------------+- - - - - - - - - - - - - - - - - -+- - -+
- * <--------- nla_data(nla) --------->
- * \endcode
- *
- * @par 1) Constructing a message with attributes
- * @code
- * int param1 = 10;
- * char *param2 = "parameter text";
- * struct nlmsghdr hdr = {
- * .nlmsg_type = MY_ACTION,
- * };
- * struct nl_msg *m = nlmsg_build(&hdr);
- * nla_put_u32(m, 1, param1);
- * nla_put_string(m, 2, param2);
- *
- * nl_send_auto_complete(handle, nl_msg_get(m));
- * nlmsg_free(m);
- * @endcode
- *
- * @par 2) Constructing nested attributes
- * @code
- * struct nl_msg * nested_config(void)
- * {
- * int a = 5, int b = 10;
- * struct nl_msg *n = nlmsg_build(NULL);
- * nla_put_u32(n, 10, a);
- * nla_put_u32(n, 20, b);
- * return n;
- * }
- *
- * ...
- * struct nl_msg *m = nlmsg_build(&hdr);
- * struct nl_msg *nest = nested_config();
- * nla_put_nested(m, 1, nest);
- *
- * nl_send_auto_complete(handle, nl_msg_get(m));
- * nlmsg_free(nest);
- * nlmsg_free(m);
- * @endcode
- * @{
- */
-
-/**
- * @name Size Calculations
- * @{
- */
-
-/**
- * length of attribute not including padding
- * @arg payload length of payload
- */
-int nla_attr_size(int payload)
-{
- return NLA_HDRLEN + payload;
-}
-
-/**
- * total length of attribute including padding
- * @arg payload length of payload
- */
-int nla_total_size(int payload)
-{
- return NLA_ALIGN(nla_attr_size(payload));
-}
-
-/**
- * length of padding at the tail of the attribute
- * @arg payload length of payload
- */
-int nla_padlen(int payload)
-{
- return nla_total_size(payload) - nla_attr_size(payload);
-}
-
-/** @} */
-
-/**
- * @name Payload Access
- * @{
- */
-
-/**
- * head of payload
- * @arg nla netlink attribute
- */
-void *nla_data(const struct nlattr *nla)
-{
- return (char *) nla + NLA_HDRLEN;
-}
-
-/**
- * length of payload
- * @arg nla netlink attribute
- */
-int nla_len(const struct nlattr *nla)
-{
- return nla->nla_len - NLA_HDRLEN;
-}
-
-/** @} */
-
-/**
- * @name Attribute Parsing
- * @{
- */
-
-/**
- * check if the netlink attribute fits into the remaining bytes
- * @arg nla netlink attribute
- * @arg remaining number of bytes remaining in attribute stream
- */
-int nla_ok(const struct nlattr *nla, int remaining)
-{
- return remaining >= sizeof(*nla) &&
- nla->nla_len >= sizeof(*nla) &&
- nla->nla_len <= remaining;
-}
-
-/**
- * next netlink attribte in attribute stream
- * @arg nla netlink attribute
- * @arg remaining number of bytes remaining in attribute stream
- *
- * @return the next netlink attribute in the attribute stream and
- * decrements remaining by the size of the current attribute.
- */
-struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
-{
- int totlen = NLA_ALIGN(nla->nla_len);
-
- *remaining -= totlen;
- return (struct nlattr *) ((char *) nla + totlen);
-}
-
-static uint16_t nla_attr_minlen[NLA_TYPE_MAX+1] = {
- [NLA_U8] = sizeof(uint8_t),
- [NLA_U16] = sizeof(uint16_t),
- [NLA_U32] = sizeof(uint32_t),
- [NLA_U64] = sizeof(uint64_t),
- [NLA_STRING] = 1,
- [NLA_NESTED] = NLA_HDRLEN,
-};
-
-static int validate_nla(struct nlattr *nla, int maxtype,
- struct nla_policy *policy)
-{
- struct nla_policy *pt;
- int minlen = 0;
-
- if (nla->nla_type <= 0 || nla->nla_type > maxtype)
- return 0;
-
- pt = &policy[nla->nla_type];
-
- if (pt->type > NLA_TYPE_MAX)
- BUG();
-
- if (pt->minlen)
- minlen = pt->minlen;
- else if (pt->type != NLA_UNSPEC)
- minlen = nla_attr_minlen[pt->type];
-
- if (pt->type == NLA_FLAG && nla_len(nla) > 0)
- return -ERANGE;
-
- if (nla_len(nla) < minlen)
- return -ERANGE;
-
- if (pt->maxlen && nla_len(nla) > pt->maxlen)
- return -ERANGE;
-
- if (pt->type == NLA_STRING) {
- char *data = nla_data(nla);
- if (data[nla_len(nla) - 1] != '\0')
- return -EINVAL;
- }
-
- return 0;
-}
-
-
-/**
- * Parse a stream of attributes into a tb buffer
- * @arg tb destination array with maxtype+1 elements
- * @arg maxtype maximum attribute type to be expected
- * @arg head head of attribute stream
- * @arg len length of attribute stream
- * @arg policy validation policy
- *
- * Parses a stream of attributes and stores a pointer to each attribute in
- * the tb array accessable via the attribute type. Attributes with a type
- * exceeding maxtype will be silently ignored for backwards compatibility
- * reasons. policy may be set to NULL if no validation is required.
- *
- * @return 0 on success or a negative error code.
- */
-int nla_parse(struct nlattr *tb[], int maxtype, struct nlattr *head, int len,
- struct nla_policy *policy)
-{
- struct nlattr *nla;
- int rem, err;
-
- memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1));
-
- nla_for_each_attr(nla, head, len, rem) {
- uint16_t type = nla->nla_type;
-
- if (type == 0) {
- fprintf(stderr, "Illegal nla->nla_type == 0\n");
- continue;
- }
-
- if (type <= maxtype) {
- if (policy) {
- err = validate_nla(nla, maxtype, policy);
- if (err < 0)
- goto errout;
- }
-
- tb[type] = nla;
- }
- }
-
- if (rem > 0)
- fprintf(stderr, "netlink: %d bytes leftover after parsing "
- "attributes.\n", rem);
-
- err = 0;
-errout:
- return err;
-}
-
-
-/**
- * parse nested attributes
- * @arg tb destination array with maxtype+1 elements
- * @arg maxtype maximum attribute type to be expected
- * @arg nla attribute containing the nested attributes
- * @arg policy validation policy
- *
- * @see nla_parse()
- */
-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);
-}
-
-/**
- * Validate a stream of attributes
- * @arg head head of attribute stream
- * @arg len length of attribute stream
- * @arg maxtype maximum attribute type to be expected
- * @arg policy validation policy
- *
- * Validates all attributes in the specified attribute stream
- * against the specified policy. Attributes with a type exceeding
- * maxtype will be ignored. See documenation of struct nla_policy
- * for more details.
- *
- * @return 0 on success or a negative error code.
- */
-int nla_validate(struct nlattr *head, int len, int maxtype,
- struct nla_policy *policy)
-{
- struct nlattr *nla;
- int rem, err;
-
- nla_for_each_attr(nla, head, len, rem) {
- err = validate_nla(nla, maxtype, policy);
- if (err < 0)
- goto errout;
- }
-
- err = 0;
-errout:
- return err;
-}
-
-/**
- * Find a specific attribute in a stream of attributes
- * @arg head head of attribute stream
- * @arg len length of attribute stream
- * @arg attrtype type of attribute to look for
- *
- * @return the first attribute in the stream matching the specified type.
- */
-struct nlattr *nla_find(struct nlattr *head, int len, int attrtype)
-{
- struct nlattr *nla;
- int rem;
-
- nla_for_each_attr(nla, head, len, rem)
- if (nla->nla_type == attrtype)
- return nla;
-
- return NULL;
-}
-
-/** @} */
-
-/**
- * @name Utilities
- * @{
- */
-
-/**
- * Copy a netlink attribute into another memory area
- * @arg dest where to copy to memcpy
- * @arg src netlink attribute to copy from
- * @arg count size of the destination area
- *
- * Note: The number of bytes copied is limited by the length of
- * attribute's payload. memcpy
- *
- * @return the number of bytes copied.
- */
-int nla_memcpy(void *dest, struct nlattr *src, int count)
-{
- int minlen;
-
- if (!src)
- return 0;
-
- minlen = min_t(int, count, nla_len(src));
- memcpy(dest, nla_data(src), minlen);
-
- return minlen;
-}
-
-/**
- * Copy string attribute payload into a sized buffer
- * @arg dst where to copy the string to
- * @arg nla attribute to copy the string from
- * @arg dstsize size of destination buffer
- *
- * Copies at most dstsize - 1 bytes into the destination buffer.
- * The result is always a valid NUL-terminated string. Unlike
- * strlcpy the destination buffer is always padded out.
- *
- * @return the length of the source buffer.
- */
-size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize)
-{
- size_t srclen = nla_len(nla);
- char *src = nla_data(nla);
-
- if (srclen > 0 && src[srclen - 1] == '\0')
- srclen--;
-
- if (dstsize > 0) {
- size_t len = (srclen >= dstsize) ? dstsize - 1 : srclen;
-
- memset(dst, 0, dstsize);
- memcpy(dst, src, len);
- }
-
- return srclen;
-}
-
-/**
- * Compare an attribute with sized memory area
- * @arg nla netlink attribute
- * @arg data memory area
- * @arg size size of memory area
- */
-int nla_memcmp(const struct nlattr *nla, const void *data,
- size_t size)
-{
- int d = nla_len(nla) - size;
-
- if (d == 0)
- d = memcmp(nla_data(nla), data, size);
-
- return d;
-}
-
-/**
- * Compare a string attribute against a string
- * @arg nla netlink string attribute
- * @arg str another string
- */
-int nla_strcmp(const struct nlattr *nla, const char *str)
-{
- int len = strlen(str) + 1;
- int d = nla_len(nla) - len;
-
- if (d == 0)
- d = memcmp(nla_data(nla), str, len);
-
- return d;
-}
-
-/** @} */
-
-/**
- * @name Attribute Construction
- * @{
- */
-
-/**
- * reserve room for attribute on the skb
- * @arg n netlink message
- * @arg attrtype attribute type
- * @arg attrlen length of attribute payload
- *
- * Adds a netlink attribute header to a netlink message and reserves
- * room for the payload but does not copy it.
- */
-struct nlattr *nla_reserve(struct nl_msg *n, int attrtype, int attrlen)
-{
- struct nlattr *nla;
- int tlen;
-
- tlen = NLMSG_ALIGN(n->nm_nlh->nlmsg_len) + nla_total_size(attrlen);
-
- n->nm_nlh = realloc(n->nm_nlh, tlen);
- if (!n->nm_nlh) {
- nl_errno(ENOMEM);
- return NULL;
- }
-
- nla = (struct nlattr *) nlmsg_tail(n->nm_nlh);
- nla->nla_type = attrtype;
- nla->nla_len = nla_attr_size(attrlen);
-
- memset((unsigned char *) nla + nla->nla_len, 0, nla_padlen(attrlen));
- n->nm_nlh->nlmsg_len = tlen;
-
- return nla;
-}
-
-/**
- * Add a netlink attribute to a netlink message
- * @arg n netlink message
- * @arg attrtype attribute type
- * @arg attrlen length of attribute payload
- * @arg data head of attribute payload
- *
- * @return -1 if the tailroom of the skb is insufficient to store
- * the attribute header and payload.
- */
-int nla_put(struct nl_msg *n, int attrtype, int attrlen, const void *data)
-{
- struct nlattr *nla;
-
- nla = nla_reserve(n, attrtype, attrlen);
- if (!nla)
- return nl_errno(ENOMEM);
-
- memcpy(nla_data(nla), data, attrlen);
-
- return 0;
-}
-
-/**
- * Add a nested netlink attribute to a netlink message
- * @arg n netlink message
- * @arg attrtype attribute type
- * @arg nested netlink attribute to nest
- *
- * @return -1 if the tailroom of the skb is insufficient to store
- * the attribute header and payload.
- */
-int nla_put_nested(struct nl_msg *n, int attrtype, struct nl_msg *nested)
-{
- return nla_put(n, attrtype, nlmsg_len(nested->nm_nlh),
- nlmsg_data(nested->nm_nlh));
-}
-
-/**
- * Add a u16 netlink attribute to a netlink message
- * @arg n netlink message
- * @arg attrtype attribute type
- * @arg value numeric value
- */
-int nla_put_u8(struct nl_msg *n, int attrtype, uint8_t value)
-{
- return nla_put(n, attrtype, sizeof(uint8_t), &value);
-}
-
-/**
- * Add a u16 netlink attribute to a netlink message
- * @arg n netlink message
- * @arg attrtype attribute type
- * @arg value numeric value
- */
-int nla_put_u16(struct nl_msg *n, int attrtype, uint16_t value)
-{
- return nla_put(n, attrtype, sizeof(uint16_t), &value);
-}
-
-/**
- * Add a u32 netlink attribute to a netlink message
- * @arg n netlink message
- * @arg attrtype attribute type
- * @arg value numeric value
- */
-int nla_put_u32(struct nl_msg *n, int attrtype, uint32_t value)
-{
- return nla_put(n, attrtype, sizeof(uint32_t), &value);
-}
-
-/**
- * Add a u64 netlink attribute to a netlink message
- * @arg n netlink message
- * @arg attrtype attribute type
- * @arg value numeric value
- */
-int nla_put_u64(struct nl_msg *n, int attrtype, uint64_t value)
-{
- return nla_put(n, attrtype, sizeof(uint64_t), &value);
-}
-
-/**
- * Add a string netlink attribute to a netlink message
- * @arg n netlink message
- * @arg attrtype attribute type
- * @arg str NUL terminated string
- */
-int nla_put_string(struct nl_msg *n, int attrtype, const char *str)
-{
- return nla_put(n, attrtype, strlen(str) + 1, str);
-}
-
-/**
- * Add a flag netlink attribute to a netlink message
- * @arg n netlink message
- * @arg attrtype attribute type
- */
-int nla_put_flag(struct nl_msg *n, int attrtype)
-{
- return nla_put(n, attrtype, 0, NULL);
-}
-
-/**
- * Add a msecs netlink attribute to a netlink message
- * @arg n netlink message
- * @arg attrtype attribute type
- * @arg msecs number of msecs
- */
-int nla_put_msecs(struct nl_msg *n, int attrtype, unsigned long msecs)
-{
- return nla_put_u64(n, attrtype, msecs);
-}
-
-/**
- * Add an abstract data netlink attribute to a netlink message
- * @arg n netlink message
- * @arg attrtype attribute type
- * @arg data abstract data
- */
-int nla_put_data(struct nl_msg *n, int attrtype, struct nl_data *data)
-{
- return nla_put(n, attrtype, nl_data_get_size(data),
- nl_data_get(data));
-}
-
-/**
- * Add an abstract address netlink attribute to a netlink message
- * @arg n netlink message
- * @arg attrtype attribute type
- * @arg addr abstract address
- */
-int nla_put_addr(struct nl_msg *n, int attrtype, struct nl_addr *addr)
-{
- return nla_put(n, attrtype, nl_addr_get_len(addr),
- nl_addr_get_binary_addr(addr));
-}
-
-/** @} */
-
-/**
- * @name Attribute Nesting
- * @{
- */
-
-/**
- * Start a new level of nested attributes
- * @arg n netlink message
- * @arg attrtype attribute type of container
- *
- * @return the container attribute
- */
-struct nlattr *nla_nest_start(struct nl_msg *n, int attrtype)
-{
- struct nlattr *start = (struct nlattr *) nlmsg_tail(n->nm_nlh);
-
- if (nla_put(n, attrtype, 0, NULL) < 0)
- return NULL;
-
- return start;
-}
-
-/**
- * Finalize nesting of attributes
- * @arg n netlink message
- * @arg start container attribute
- *
- * Corrects the container attribute header to include the all
- * appeneded attributes.
- *
- * @return the total data length of the skb.
- */
-int nla_nest_end(struct nl_msg *n, struct nlattr *start)
-{
- start->nla_len = (unsigned char *) nlmsg_tail(n->nm_nlh) -
- (unsigned char *) start;
- return 0;
-}
-
-/** @} */
-
-/**
- * @name Attribute Reading
- * @{
- */
-
-/**
- * Return payload of u32 attribute
- * @arg nla u32 netlink attribute
- */
-uint32_t nla_get_u32(struct nlattr *nla)
-{
- return *(uint32_t *) nla_data(nla);
-}
-
-/**
- * Return payload of u16 attribute
- * @arg nla u16 netlink attribute
- */
-uint16_t nla_get_u16(struct nlattr *nla)
-{
- return *(uint16_t *) nla_data(nla);
-}
-
-/**
- * Return payload of u8 attribute
- * @arg nla u8 netlink attribute
- */
-uint8_t nla_get_u8(struct nlattr *nla)
-{
- return *(uint8_t *) nla_data(nla);
-}
-
-/**
- * Return payload of u64 attribute
- * @arg nla u64 netlink attribute
- */
-uint64_t nla_get_u64(struct nlattr *nla)
-{
- uint64_t tmp;
-
- nla_memcpy(&tmp, nla, sizeof(tmp));
-
- return tmp;
-}
-
-/**
- * Return payload of flag attribute
- * @arg nla flag netlink attribute
- */
-int nla_get_flag(struct nlattr *nla)
-{
- return !!nla;
-}
-
-/**
- * Return payload of msecs attribute
- * @arg nla msecs netlink attribute
- *
- * @return the number of milliseconds.
- */
-unsigned long nla_get_msecs(struct nlattr *nla)
-{
- return nla_get_u64(nla);
-}
-
-/**
- * Return payload of address attribute
- * @arg nla address netlink attribute
- * @arg family address family
- *
- * @return Newly allocated address handle or NULL
- */
-struct nl_addr *nla_get_addr(struct nlattr *nla, int family)
-{
- return nl_addr_build(family, nla_data(nla), nla_len(nla));
-}
-
-/**
- * Return payload of abstract data attribute
- * @arg nla abstract data netlink attribute
- *
- * @return Newly allocated abstract data handle or NULL
- */
-struct nl_data *nla_get_data(struct nlattr *nla)
-{
- return nl_data_alloc(nla_data(nla), nla_len(nla));
-}
-
-/** @} */
-
-/** @} */
git://git.onelab.eu / libnl.git / blobdiff