From e9cc8bddaea3944fabfebb968bc88d603239beed Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Wed, 4 Mar 2009 14:53:30 +0800 Subject: netlink: Move netlink attribute parsing support to lib Netlink attribute parsing may be used even if CONFIG_NET is not set. Move it from net/netlink to lib and control its inclusion based on the new config symbol CONFIG_NLATTR, which is selected by CONFIG_NET. Signed-off-by: Geert Uytterhoeven Acked-by: David S. Miller Signed-off-by: Herbert Xu --- lib/Kconfig | 6 + lib/Makefile | 2 + lib/nlattr.c | 473 +++++++++++++++++++++++++++++++++++++++++++++++++++ net/Kconfig | 1 + net/netlink/Makefile | 2 +- net/netlink/attr.c | 473 --------------------------------------------------- 6 files changed, 483 insertions(+), 474 deletions(-) create mode 100644 lib/nlattr.c delete mode 100644 net/netlink/attr.c diff --git a/lib/Kconfig b/lib/Kconfig index 03c2c24b908..cea9e30a88f 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -174,4 +174,10 @@ config DISABLE_OBSOLETE_CPUMASK_FUNCTIONS bool "Disable obsolete cpumask functions" if DEBUG_PER_CPU_MAPS depends on EXPERIMENTAL && BROKEN +# +# Netlink attribute parsing support is select'ed if needed +# +config NLATTR + bool + endmenu diff --git a/lib/Makefile b/lib/Makefile index 32b0e64ded2..b2c09da02ca 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -84,6 +84,8 @@ obj-$(CONFIG_HAVE_ARCH_TRACEHOOK) += syscall.o obj-$(CONFIG_DYNAMIC_PRINTK_DEBUG) += dynamic_printk.o +obj-$(CONFIG_NLATTR) += nlattr.o + hostprogs-y := gen_crc32table clean-files := crc32table.h diff --git a/lib/nlattr.c b/lib/nlattr.c new file mode 100644 index 00000000000..56c3ce7fe29 --- /dev/null +++ b/lib/nlattr.c @@ -0,0 +1,473 @@ +/* + * NETLINK Netlink attributes + * + * Authors: Thomas Graf + * Alexey Kuznetsov + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static u16 nla_attr_minlen[NLA_TYPE_MAX+1] __read_mostly = { + [NLA_U8] = sizeof(u8), + [NLA_U16] = sizeof(u16), + [NLA_U32] = sizeof(u32), + [NLA_U64] = sizeof(u64), + [NLA_NESTED] = NLA_HDRLEN, +}; + +static int validate_nla(struct nlattr *nla, int maxtype, + const struct nla_policy *policy) +{ + const struct nla_policy *pt; + int minlen = 0, attrlen = nla_len(nla), type = nla_type(nla); + + if (type <= 0 || type > maxtype) + return 0; + + pt = &policy[type]; + + BUG_ON(pt->type > NLA_TYPE_MAX); + + switch (pt->type) { + case NLA_FLAG: + if (attrlen > 0) + return -ERANGE; + break; + + case NLA_NUL_STRING: + if (pt->len) + minlen = min_t(int, attrlen, pt->len + 1); + else + minlen = attrlen; + + if (!minlen || memchr(nla_data(nla), '\0', minlen) == NULL) + return -EINVAL; + /* fall through */ + + case NLA_STRING: + if (attrlen < 1) + return -ERANGE; + + if (pt->len) { + char *buf = nla_data(nla); + + if (buf[attrlen - 1] == '\0') + attrlen--; + + if (attrlen > pt->len) + return -ERANGE; + } + break; + + case NLA_BINARY: + if (pt->len && attrlen > pt->len) + return -ERANGE; + break; + + case NLA_NESTED_COMPAT: + if (attrlen < pt->len) + return -ERANGE; + if (attrlen < NLA_ALIGN(pt->len)) + break; + if (attrlen < NLA_ALIGN(pt->len) + NLA_HDRLEN) + return -ERANGE; + nla = nla_data(nla) + NLA_ALIGN(pt->len); + if (attrlen < NLA_ALIGN(pt->len) + NLA_HDRLEN + nla_len(nla)) + return -ERANGE; + break; + case NLA_NESTED: + /* a nested attributes is allowed to be empty; if its not, + * it must have a size of at least NLA_HDRLEN. + */ + if (attrlen == 0) + break; + default: + if (pt->len) + minlen = pt->len; + else if (pt->type != NLA_UNSPEC) + minlen = nla_attr_minlen[pt->type]; + + if (attrlen < minlen) + return -ERANGE; + } + + return 0; +} + +/** + * nla_validate - Validate a stream of attributes + * @head: head of attribute stream + * @len: length of attribute stream + * @maxtype: maximum attribute type to be expected + * @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. + * + * Returns 0 on success or a negative error code. + */ +int nla_validate(struct nlattr *head, int len, int maxtype, + const 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; +} + +/** + * nla_parse - Parse a stream of attributes into a tb buffer + * @tb: destination array with maxtype+1 elements + * @maxtype: maximum attribute type to be expected + * @head: head of attribute stream + * @len: length of attribute stream + * @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. + * + * Returns 0 on success or a negative error code. + */ +int nla_parse(struct nlattr *tb[], int maxtype, struct nlattr *head, int len, + const 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) { + u16 type = nla_type(nla); + + if (type > 0 && type <= maxtype) { + if (policy) { + err = validate_nla(nla, maxtype, policy); + if (err < 0) + goto errout; + } + + tb[type] = nla; + } + } + + if (unlikely(rem > 0)) + printk(KERN_WARNING "netlink: %d bytes leftover after parsing " + "attributes.\n", rem); + + err = 0; +errout: + return err; +} + +/** + * nla_find - Find a specific attribute in a stream of attributes + * @head: head of attribute stream + * @len: length of attribute stream + * @attrtype: type of attribute to look for + * + * Returns 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_type(nla) == attrtype) + return nla; + + return NULL; +} + +/** + * nla_strlcpy - Copy string attribute payload into a sized buffer + * @dst: where to copy the string to + * @nla: attribute to copy the string from + * @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. + * + * Returns 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; +} + +/** + * nla_memcpy - Copy a netlink attribute into another memory area + * @dest: where to copy to memcpy + * @src: netlink attribute to copy from + * @count: size of the destination area + * + * Note: The number of bytes copied is limited by the length of + * attribute's payload. memcpy + * + * Returns the number of bytes copied. + */ +int nla_memcpy(void *dest, const struct nlattr *src, int count) +{ + int minlen = min_t(int, count, nla_len(src)); + + memcpy(dest, nla_data(src), minlen); + + return minlen; +} + +/** + * nla_memcmp - Compare an attribute with sized memory area + * @nla: netlink attribute + * @data: memory area + * @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; +} + +/** + * nla_strcmp - Compare a string attribute against a string + * @nla: netlink string attribute + * @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; +} + +/** + * __nla_reserve - reserve room for attribute on the skb + * @skb: socket buffer to reserve room on + * @attrtype: attribute type + * @attrlen: length of attribute payload + * + * Adds a netlink attribute header to a socket buffer and reserves + * room for the payload but does not copy it. + * + * The caller is responsible to ensure that the skb provides enough + * tailroom for the attribute header and payload. + */ +struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen) +{ + struct nlattr *nla; + + nla = (struct nlattr *) skb_put(skb, nla_total_size(attrlen)); + nla->nla_type = attrtype; + nla->nla_len = nla_attr_size(attrlen); + + memset((unsigned char *) nla + nla->nla_len, 0, nla_padlen(attrlen)); + + return nla; +} + +/** + * __nla_reserve_nohdr - reserve room for attribute without header + * @skb: socket buffer to reserve room on + * @attrlen: length of attribute payload + * + * Reserves room for attribute payload without a header. + * + * The caller is responsible to ensure that the skb provides enough + * tailroom for the payload. + */ +void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen) +{ + void *start; + + start = skb_put(skb, NLA_ALIGN(attrlen)); + memset(start, 0, NLA_ALIGN(attrlen)); + + return start; +} + +/** + * nla_reserve - reserve room for attribute on the skb + * @skb: socket buffer to reserve room on + * @attrtype: attribute type + * @attrlen: length of attribute payload + * + * Adds a netlink attribute header to a socket buffer and reserves + * room for the payload but does not copy it. + * + * Returns NULL if the tailroom of the skb is insufficient to store + * the attribute header and payload. + */ +struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen) +{ + if (unlikely(skb_tailroom(skb) < nla_total_size(attrlen))) + return NULL; + + return __nla_reserve(skb, attrtype, attrlen); +} + +/** + * nla_reserve_nohdr - reserve room for attribute without header + * @skb: socket buffer to reserve room on + * @attrlen: length of attribute payload + * + * Reserves room for attribute payload without a header. + * + * Returns NULL if the tailroom of the skb is insufficient to store + * the attribute payload. + */ +void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen) +{ + if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen))) + return NULL; + + return __nla_reserve_nohdr(skb, attrlen); +} + +/** + * __nla_put - Add a netlink attribute to a socket buffer + * @skb: socket buffer to add attribute to + * @attrtype: attribute type + * @attrlen: length of attribute payload + * @data: head of attribute payload + * + * The caller is responsible to ensure that the skb provides enough + * tailroom for the attribute header and payload. + */ +void __nla_put(struct sk_buff *skb, int attrtype, int attrlen, + const void *data) +{ + struct nlattr *nla; + + nla = __nla_reserve(skb, attrtype, attrlen); + memcpy(nla_data(nla), data, attrlen); +} + +/** + * __nla_put_nohdr - Add a netlink attribute without header + * @skb: socket buffer to add attribute to + * @attrlen: length of attribute payload + * @data: head of attribute payload + * + * The caller is responsible to ensure that the skb provides enough + * tailroom for the attribute payload. + */ +void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data) +{ + void *start; + + start = __nla_reserve_nohdr(skb, attrlen); + memcpy(start, data, attrlen); +} + +/** + * nla_put - Add a netlink attribute to a socket buffer + * @skb: socket buffer to add attribute to + * @attrtype: attribute type + * @attrlen: length of attribute payload + * @data: head of attribute payload + * + * Returns -EMSGSIZE if the tailroom of the skb is insufficient to store + * the attribute header and payload. + */ +int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data) +{ + if (unlikely(skb_tailroom(skb) < nla_total_size(attrlen))) + return -EMSGSIZE; + + __nla_put(skb, attrtype, attrlen, data); + return 0; +} + +/** + * nla_put_nohdr - Add a netlink attribute without header + * @skb: socket buffer to add attribute to + * @attrlen: length of attribute payload + * @data: head of attribute payload + * + * Returns -EMSGSIZE if the tailroom of the skb is insufficient to store + * the attribute payload. + */ +int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data) +{ + if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen))) + return -EMSGSIZE; + + __nla_put_nohdr(skb, attrlen, data); + return 0; +} + +/** + * nla_append - Add a netlink attribute without header or padding + * @skb: socket buffer to add attribute to + * @attrlen: length of attribute payload + * @data: head of attribute payload + * + * Returns -EMSGSIZE if the tailroom of the skb is insufficient to store + * the attribute payload. + */ +int nla_append(struct sk_buff *skb, int attrlen, const void *data) +{ + if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen))) + return -EMSGSIZE; + + memcpy(skb_put(skb, attrlen), data, attrlen); + return 0; +} + +EXPORT_SYMBOL(nla_validate); +EXPORT_SYMBOL(nla_parse); +EXPORT_SYMBOL(nla_find); +EXPORT_SYMBOL(nla_strlcpy); +EXPORT_SYMBOL(__nla_reserve); +EXPORT_SYMBOL(__nla_reserve_nohdr); +EXPORT_SYMBOL(nla_reserve); +EXPORT_SYMBOL(nla_reserve_nohdr); +EXPORT_SYMBOL(__nla_put); +EXPORT_SYMBOL(__nla_put_nohdr); +EXPORT_SYMBOL(nla_put); +EXPORT_SYMBOL(nla_put_nohdr); +EXPORT_SYMBOL(nla_memcpy); +EXPORT_SYMBOL(nla_memcmp); +EXPORT_SYMBOL(nla_strcmp); +EXPORT_SYMBOL(nla_append); diff --git a/net/Kconfig b/net/Kconfig index cdb8fdef6c4..eab40a48135 100644 --- a/net/Kconfig +++ b/net/Kconfig @@ -4,6 +4,7 @@ menuconfig NET bool "Networking support" + select NLATTR ---help--- Unless you really know what you are doing, you should say Y here. The reason is that some programs need kernel networking support even diff --git a/net/netlink/Makefile b/net/netlink/Makefile index e3589c2de49..bdd6ddf4e95 100644 --- a/net/netlink/Makefile +++ b/net/netlink/Makefile @@ -2,4 +2,4 @@ # Makefile for the netlink driver. # -obj-y := af_netlink.o attr.o genetlink.o +obj-y := af_netlink.o genetlink.o diff --git a/net/netlink/attr.c b/net/netlink/attr.c deleted file mode 100644 index 56c3ce7fe29..00000000000 --- a/net/netlink/attr.c +++ /dev/null @@ -1,473 +0,0 @@ -/* - * NETLINK Netlink attributes - * - * Authors: Thomas Graf - * Alexey Kuznetsov - */ - -#include -#include -#include -#include -#include -#include -#include -#include -#include - -static u16 nla_attr_minlen[NLA_TYPE_MAX+1] __read_mostly = { - [NLA_U8] = sizeof(u8), - [NLA_U16] = sizeof(u16), - [NLA_U32] = sizeof(u32), - [NLA_U64] = sizeof(u64), - [NLA_NESTED] = NLA_HDRLEN, -}; - -static int validate_nla(struct nlattr *nla, int maxtype, - const struct nla_policy *policy) -{ - const struct nla_policy *pt; - int minlen = 0, attrlen = nla_len(nla), type = nla_type(nla); - - if (type <= 0 || type > maxtype) - return 0; - - pt = &policy[type]; - - BUG_ON(pt->type > NLA_TYPE_MAX); - - switch (pt->type) { - case NLA_FLAG: - if (attrlen > 0) - return -ERANGE; - break; - - case NLA_NUL_STRING: - if (pt->len) - minlen = min_t(int, attrlen, pt->len + 1); - else - minlen = attrlen; - - if (!minlen || memchr(nla_data(nla), '\0', minlen) == NULL) - return -EINVAL; - /* fall through */ - - case NLA_STRING: - if (attrlen < 1) - return -ERANGE; - - if (pt->len) { - char *buf = nla_data(nla); - - if (buf[attrlen - 1] == '\0') - attrlen--; - - if (attrlen > pt->len) - return -ERANGE; - } - break; - - case NLA_BINARY: - if (pt->len && attrlen > pt->len) - return -ERANGE; - break; - - case NLA_NESTED_COMPAT: - if (attrlen < pt->len) - return -ERANGE; - if (attrlen < NLA_ALIGN(pt->len)) - break; - if (attrlen < NLA_ALIGN(pt->len) + NLA_HDRLEN) - return -ERANGE; - nla = nla_data(nla) + NLA_ALIGN(pt->len); - if (attrlen < NLA_ALIGN(pt->len) + NLA_HDRLEN + nla_len(nla)) - return -ERANGE; - break; - case NLA_NESTED: - /* a nested attributes is allowed to be empty; if its not, - * it must have a size of at least NLA_HDRLEN. - */ - if (attrlen == 0) - break; - default: - if (pt->len) - minlen = pt->len; - else if (pt->type != NLA_UNSPEC) - minlen = nla_attr_minlen[pt->type]; - - if (attrlen < minlen) - return -ERANGE; - } - - return 0; -} - -/** - * nla_validate - Validate a stream of attributes - * @head: head of attribute stream - * @len: length of attribute stream - * @maxtype: maximum attribute type to be expected - * @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. - * - * Returns 0 on success or a negative error code. - */ -int nla_validate(struct nlattr *head, int len, int maxtype, - const 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; -} - -/** - * nla_parse - Parse a stream of attributes into a tb buffer - * @tb: destination array with maxtype+1 elements - * @maxtype: maximum attribute type to be expected - * @head: head of attribute stream - * @len: length of attribute stream - * @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. - * - * Returns 0 on success or a negative error code. - */ -int nla_parse(struct nlattr *tb[], int maxtype, struct nlattr *head, int len, - const 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) { - u16 type = nla_type(nla); - - if (type > 0 && type <= maxtype) { - if (policy) { - err = validate_nla(nla, maxtype, policy); - if (err < 0) - goto errout; - } - - tb[type] = nla; - } - } - - if (unlikely(rem > 0)) - printk(KERN_WARNING "netlink: %d bytes leftover after parsing " - "attributes.\n", rem); - - err = 0; -errout: - return err; -} - -/** - * nla_find - Find a specific attribute in a stream of attributes - * @head: head of attribute stream - * @len: length of attribute stream - * @attrtype: type of attribute to look for - * - * Returns 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_type(nla) == attrtype) - return nla; - - return NULL; -} - -/** - * nla_strlcpy - Copy string attribute payload into a sized buffer - * @dst: where to copy the string to - * @nla: attribute to copy the string from - * @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. - * - * Returns 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; -} - -/** - * nla_memcpy - Copy a netlink attribute into another memory area - * @dest: where to copy to memcpy - * @src: netlink attribute to copy from - * @count: size of the destination area - * - * Note: The number of bytes copied is limited by the length of - * attribute's payload. memcpy - * - * Returns the number of bytes copied. - */ -int nla_memcpy(void *dest, const struct nlattr *src, int count) -{ - int minlen = min_t(int, count, nla_len(src)); - - memcpy(dest, nla_data(src), minlen); - - return minlen; -} - -/** - * nla_memcmp - Compare an attribute with sized memory area - * @nla: netlink attribute - * @data: memory area - * @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; -} - -/** - * nla_strcmp - Compare a string attribute against a string - * @nla: netlink string attribute - * @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; -} - -/** - * __nla_reserve - reserve room for attribute on the skb - * @skb: socket buffer to reserve room on - * @attrtype: attribute type - * @attrlen: length of attribute payload - * - * Adds a netlink attribute header to a socket buffer and reserves - * room for the payload but does not copy it. - * - * The caller is responsible to ensure that the skb provides enough - * tailroom for the attribute header and payload. - */ -struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen) -{ - struct nlattr *nla; - - nla = (struct nlattr *) skb_put(skb, nla_total_size(attrlen)); - nla->nla_type = attrtype; - nla->nla_len = nla_attr_size(attrlen); - - memset((unsigned char *) nla + nla->nla_len, 0, nla_padlen(attrlen)); - - return nla; -} - -/** - * __nla_reserve_nohdr - reserve room for attribute without header - * @skb: socket buffer to reserve room on - * @attrlen: length of attribute payload - * - * Reserves room for attribute payload without a header. - * - * The caller is responsible to ensure that the skb provides enough - * tailroom for the payload. - */ -void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen) -{ - void *start; - - start = skb_put(skb, NLA_ALIGN(attrlen)); - memset(start, 0, NLA_ALIGN(attrlen)); - - return start; -} - -/** - * nla_reserve - reserve room for attribute on the skb - * @skb: socket buffer to reserve room on - * @attrtype: attribute type - * @attrlen: length of attribute payload - * - * Adds a netlink attribute header to a socket buffer and reserves - * room for the payload but does not copy it. - * - * Returns NULL if the tailroom of the skb is insufficient to store - * the attribute header and payload. - */ -struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen) -{ - if (unlikely(skb_tailroom(skb) < nla_total_size(attrlen))) - return NULL; - - return __nla_reserve(skb, attrtype, attrlen); -} - -/** - * nla_reserve_nohdr - reserve room for attribute without header - * @skb: socket buffer to reserve room on - * @attrlen: length of attribute payload - * - * Reserves room for attribute payload without a header. - * - * Returns NULL if the tailroom of the skb is insufficient to store - * the attribute payload. - */ -void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen) -{ - if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen))) - return NULL; - - return __nla_reserve_nohdr(skb, attrlen); -} - -/** - * __nla_put - Add a netlink attribute to a socket buffer - * @skb: socket buffer to add attribute to - * @attrtype: attribute type - * @attrlen: length of attribute payload - * @data: head of attribute payload - * - * The caller is responsible to ensure that the skb provides enough - * tailroom for the attribute header and payload. - */ -void __nla_put(struct sk_buff *skb, int attrtype, int attrlen, - const void *data) -{ - struct nlattr *nla; - - nla = __nla_reserve(skb, attrtype, attrlen); - memcpy(nla_data(nla), data, attrlen); -} - -/** - * __nla_put_nohdr - Add a netlink attribute without header - * @skb: socket buffer to add attribute to - * @attrlen: length of attribute payload - * @data: head of attribute payload - * - * The caller is responsible to ensure that the skb provides enough - * tailroom for the attribute payload. - */ -void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data) -{ - void *start; - - start = __nla_reserve_nohdr(skb, attrlen); - memcpy(start, data, attrlen); -} - -/** - * nla_put - Add a netlink attribute to a socket buffer - * @skb: socket buffer to add attribute to - * @attrtype: attribute type - * @attrlen: length of attribute payload - * @data: head of attribute payload - * - * Returns -EMSGSIZE if the tailroom of the skb is insufficient to store - * the attribute header and payload. - */ -int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data) -{ - if (unlikely(skb_tailroom(skb) < nla_total_size(attrlen))) - return -EMSGSIZE; - - __nla_put(skb, attrtype, attrlen, data); - return 0; -} - -/** - * nla_put_nohdr - Add a netlink attribute without header - * @skb: socket buffer to add attribute to - * @attrlen: length of attribute payload - * @data: head of attribute payload - * - * Returns -EMSGSIZE if the tailroom of the skb is insufficient to store - * the attribute payload. - */ -int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data) -{ - if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen))) - return -EMSGSIZE; - - __nla_put_nohdr(skb, attrlen, data); - return 0; -} - -/** - * nla_append - Add a netlink attribute without header or padding - * @skb: socket buffer to add attribute to - * @attrlen: length of attribute payload - * @data: head of attribute payload - * - * Returns -EMSGSIZE if the tailroom of the skb is insufficient to store - * the attribute payload. - */ -int nla_append(struct sk_buff *skb, int attrlen, const void *data) -{ - if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen))) - return -EMSGSIZE; - - memcpy(skb_put(skb, attrlen), data, attrlen); - return 0; -} - -EXPORT_SYMBOL(nla_validate); -EXPORT_SYMBOL(nla_parse); -EXPORT_SYMBOL(nla_find); -EXPORT_SYMBOL(nla_strlcpy); -EXPORT_SYMBOL(__nla_reserve); -EXPORT_SYMBOL(__nla_reserve_nohdr); -EXPORT_SYMBOL(nla_reserve); -EXPORT_SYMBOL(nla_reserve_nohdr); -EXPORT_SYMBOL(__nla_put); -EXPORT_SYMBOL(__nla_put_nohdr); -EXPORT_SYMBOL(nla_put); -EXPORT_SYMBOL(nla_put_nohdr); -EXPORT_SYMBOL(nla_memcpy); -EXPORT_SYMBOL(nla_memcmp); -EXPORT_SYMBOL(nla_strcmp); -EXPORT_SYMBOL(nla_append); -- cgit v1.2.3