diff options
| -rw-r--r-- | include/net/netlink.h | 84 | ||||
| -rw-r--r-- | net/netlink/attr.c | 11 |
2 files changed, 95 insertions, 0 deletions
diff --git a/include/net/netlink.h b/include/net/netlink.h index 7b510a9edb91..d7b824be5422 100644 --- a/include/net/netlink.h +++ b/include/net/netlink.h @@ -118,6 +118,9 @@ * Nested Attributes Construction: * nla_nest_start(skb, type) start a nested attribute * nla_nest_end(skb, nla) finalize a nested attribute + * nla_nest_compat_start(skb, type, start a nested compat attribute + * len, data) + * nla_nest_compat_end(skb, type) finalize a nested compat attribute * nla_nest_cancel(skb, nla) cancel nested attribute construction * * Attribute Length Calculations: @@ -152,6 +155,7 @@ * nla_find_nested() find attribute in nested attributes * nla_parse() parse and validate stream of attrs * nla_parse_nested() parse nested attribuets + * nla_parse_nested_compat() parse nested compat attributes * nla_for_each_attr() loop over all attributes * nla_for_each_nested() loop over the nested attributes *========================================================================= @@ -170,6 +174,7 @@ enum { NLA_FLAG, NLA_MSECS, NLA_NESTED, + NLA_NESTED_COMPAT, NLA_NUL_STRING, NLA_BINARY, __NLA_TYPE_MAX, @@ -190,6 +195,7 @@ enum { * NLA_NUL_STRING Maximum length of string (excluding NUL) * NLA_FLAG Unused * NLA_BINARY Maximum length of attribute payload + * NLA_NESTED_COMPAT Exact length of structure payload * All other Exact length of attribute payload * * Example: @@ -733,6 +739,39 @@ static inline int nla_parse_nested(struct nlattr *tb[], int maxtype, { return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy); } + +/** + * nla_parse_nested_compat - parse nested compat attributes + * @tb: destination array with maxtype+1 elements + * @maxtype: maximum attribute type to be expected + * @nla: attribute containing the nested attributes + * @data: pointer to point to contained structure + * @len: length of contained structure + * @policy: validation policy + * + * Parse a nested compat attribute. The compat attribute contains a structure + * and optionally a set of nested attributes. On success the data pointer + * points to the nested data and tb contains the parsed attributes + * (see nla_parse). + */ +static inline int __nla_parse_nested_compat(struct nlattr *tb[], int maxtype, + struct nlattr *nla, + const struct nla_policy *policy, + int len) +{ + if (nla_len(nla) < len) + return -1; + if (nla_len(nla) >= NLA_ALIGN(len) + sizeof(struct nlattr)) + return nla_parse_nested(tb, maxtype, + nla_data(nla) + NLA_ALIGN(len), + policy); + memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1)); + return 0; +} + +#define nla_parse_nested_compat(tb, maxtype, nla, policy, data, len) \ +({ data = nla_len(nla) >= len ? nla_data(nla) : NULL; \ + __nla_parse_nested_compat(tb, maxtype, nla, policy, len); }) /** * nla_put_u8 - Add a u16 netlink attribute to a socket buffer * @skb: socket buffer to add attribute to @@ -965,6 +1004,51 @@ static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start) } /** + * nla_nest_compat_start - Start a new level of nested compat attributes + * @skb: socket buffer to add attributes to + * @attrtype: attribute type of container + * @attrlen: length of structure + * @data: pointer to structure + * + * Start a nested compat attribute that contains both a structure and + * a set of nested attributes. + * + * Returns the container attribute + */ +static inline struct nlattr *nla_nest_compat_start(struct sk_buff *skb, + int attrtype, int attrlen, + const void *data) +{ + struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb); + + if (nla_put(skb, attrtype, attrlen, data) < 0) + return NULL; + if (nla_nest_start(skb, attrtype) == NULL) { + nlmsg_trim(skb, start); + return NULL; + } + return start; +} + +/** + * nla_nest_compat_end - Finalize nesting of compat attributes + * @skb: socket buffer the attribtues are stored in + * @start: container attribute + * + * Corrects the container attribute header to include the all + * appeneded attributes. + * + * Returns the total data length of the skb. + */ +static inline int nla_nest_compat_end(struct sk_buff *skb, struct nlattr *start) +{ + struct nlattr *nest = (void *)start + NLMSG_ALIGN(start->nla_len); + + start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start; + return nla_nest_end(skb, nest); +} + +/** * nla_nest_cancel - Cancel nesting of attributes * @skb: socket buffer the message is stored in * @start: container attribute diff --git a/net/netlink/attr.c b/net/netlink/attr.c index c591212793ee..e4d7bed99c2e 100644 --- a/net/netlink/attr.c +++ b/net/netlink/attr.c @@ -72,6 +72,17 @@ static int validate_nla(struct nlattr *nla, int maxtype, 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; default: if (pt->len) minlen = pt->len; |