From a5531a5d852008be40811496029012f4ad3093d1 Mon Sep 17 00:00:00 2001 From: Thomas Graf Date: Sat, 26 Aug 2006 20:11:47 -0700 Subject: [NETLINK]: Improve string attribute validation Introduces a new attribute type NLA_NUL_STRING to support NUL terminated strings. Attributes of this kind require to carry a terminating NUL within the maximum specified in the policy. The `old' NLA_STRING which is not required to be NUL terminated is extended to provide means to specify a maximum length of the string. Aims at easing the pain with using nla_strlcpy() on temporary buffers. Signed-off-by: Thomas Graf Signed-off-by: David S. Miller --- include/net/netlink.h | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) (limited to 'include/net/netlink.h') diff --git a/include/net/netlink.h b/include/net/netlink.h index bcb27e3a312..11dc2e7f679 100644 --- a/include/net/netlink.h +++ b/include/net/netlink.h @@ -167,6 +167,7 @@ enum { NLA_FLAG, NLA_MSECS, NLA_NESTED, + NLA_NUL_STRING, __NLA_TYPE_MAX, }; @@ -175,21 +176,27 @@ enum { /** * struct nla_policy - attribute validation policy * @type: Type of attribute or NLA_UNSPEC - * @minlen: Minimal length of payload required to be available + * @len: Type specific length of payload * * Policies are defined as arrays of this struct, the array must be * accessible by attribute type up to the highest identifier to be expected. * + * Meaning of `len' field: + * NLA_STRING Maximum length of string + * NLA_NUL_STRING Maximum length of string (excluding NUL) + * NLA_FLAG Unused + * All other Exact length of attribute payload + * * Example: * static struct nla_policy my_policy[ATTR_MAX+1] __read_mostly = { * [ATTR_FOO] = { .type = NLA_U16 }, - * [ATTR_BAR] = { .type = NLA_STRING }, - * [ATTR_BAZ] = { .minlen = sizeof(struct mystruct) }, + * [ATTR_BAR] = { .type = NLA_STRING, len = BARSIZ }, + * [ATTR_BAZ] = { .len = sizeof(struct mystruct) }, * }; */ struct nla_policy { u16 type; - u16 minlen; + u16 len; }; /** -- cgit v1.2.3