From fe4944e59c357f945f81bc67edb7ed1392e875ad Mon Sep 17 00:00:00 2001 From: Thomas Graf Date: Fri, 4 Aug 2006 23:03:05 -0700 Subject: [NETLINK]: Extend netlink messaging interface Adds: nlmsg_get_pos() return current position in message nlmsg_trim() trim part of message nla_reserve_nohdr(skb, len) reserve room for an attribute w/o hdr nla_put_nohdr(skb, len, data) add attribute w/o hdr nla_find_nested() find attribute in nested attributes Fixes nlmsg_new() to take allocation flags and consider size. Signed-off-by: Thomas Graf Signed-off-by: David S. Miller --- net/netlink/attr.c | 75 +++++++++++++++++++++++++++++++++++++++++++++++++ net/netlink/genetlink.c | 2 +- 2 files changed, 76 insertions(+), 1 deletion(-) (limited to 'net/netlink') diff --git a/net/netlink/attr.c b/net/netlink/attr.c index dddbd15135a..136e529e578 100644 --- a/net/netlink/attr.c +++ b/net/netlink/attr.c @@ -254,6 +254,26 @@ struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int 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 @@ -274,6 +294,24 @@ struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen) return __nla_reserve(skb, attrtype, attrlen); } +/** + * nla_reserve - reserve room for attribute without header + * @skb: socket buffer to reserve room on + * @len: 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 @@ -293,6 +331,22 @@ void __nla_put(struct sk_buff *skb, int attrtype, int 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 @@ -313,15 +367,36 @@ int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *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 -1 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 -1; + + __nla_put_nohdr(skb, attrlen, data); + 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); diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c index a298f77cc3e..75bb47a898d 100644 --- a/net/netlink/genetlink.c +++ b/net/netlink/genetlink.c @@ -440,7 +440,7 @@ static struct sk_buff *ctrl_build_msg(struct genl_family *family, u32 pid, struct sk_buff *skb; int err; - skb = nlmsg_new(NLMSG_GOODSIZE); + skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL); if (skb == NULL) return ERR_PTR(-ENOBUFS); -- cgit v1.2.3-70-g09d2