From 3654654f7aa79a37dde130afb7409c55b11807e7 Mon Sep 17 00:00:00 2001 From: Jan Engelhardt Date: Tue, 16 Nov 2010 09:52:32 -0800 Subject: [PATCH] netlink: let nlmsg and nla functions take pointer-to-const args The changed functions do not modify the NL messages and/or attributes at all. They should use const (similar to strchr), so that callers which have a const nlmsg/nlattr around can make use of them without casting. While at it, constify a data array. Signed-off-by: Jan Engelhardt Signed-off-by: David S. Miller --- include/net/netlink.h | 21 +++++++++++++-------- lib/nlattr.c | 22 +++++++++++----------- 2 files changed, 24 insertions(+), 19 deletions(-) diff --git a/include/net/netlink.h b/include/net/netlink.h index 9801c55de5d..373f1a900cf 100644 --- a/include/net/netlink.h +++ b/include/net/netlink.h @@ -225,13 +225,15 @@ extern int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 pid, unsigned int group, int report, gfp_t flags); -extern int nla_validate(struct nlattr *head, int len, int maxtype, +extern int nla_validate(const struct nlattr *head, + int len, int maxtype, const struct nla_policy *policy); -extern int nla_parse(struct nlattr *tb[], int maxtype, - struct nlattr *head, int len, +extern int nla_parse(struct nlattr **tb, int maxtype, + const struct nlattr *head, int len, const struct nla_policy *policy); extern int nla_policy_len(const struct nla_policy *, int); -extern struct nlattr * nla_find(struct nlattr *head, int len, int attrtype); +extern struct nlattr * nla_find(const struct nlattr *head, + int len, int attrtype); extern size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize); extern int nla_memcpy(void *dest, const struct nlattr *src, int count); @@ -346,7 +348,8 @@ static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining) * Returns the next netlink message in the message stream and * decrements remaining by the size of the current message. */ -static inline struct nlmsghdr *nlmsg_next(struct nlmsghdr *nlh, int *remaining) +static inline struct nlmsghdr * +nlmsg_next(const struct nlmsghdr *nlh, int *remaining) { int totlen = NLMSG_ALIGN(nlh->nlmsg_len); @@ -398,7 +401,8 @@ static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh, * @maxtype: maximum attribute type to be expected * @policy: validation policy */ -static inline int nlmsg_validate(struct nlmsghdr *nlh, int hdrlen, int maxtype, +static inline int nlmsg_validate(const struct nlmsghdr *nlh, + int hdrlen, int maxtype, const struct nla_policy *policy) { if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) @@ -727,7 +731,8 @@ static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining) * * Returns the first attribute which matches the specified type. */ -static inline struct nlattr *nla_find_nested(struct nlattr *nla, int attrtype) +static inline struct nlattr * +nla_find_nested(const struct nlattr *nla, int attrtype) { return nla_find(nla_data(nla), nla_len(nla), attrtype); } @@ -1032,7 +1037,7 @@ static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start) * * Returns 0 on success or a negative error code. */ -static inline int nla_validate_nested(struct nlattr *start, int maxtype, +static inline int nla_validate_nested(const struct nlattr *start, int maxtype, const struct nla_policy *policy) { return nla_validate(nla_data(start), nla_len(start), maxtype, policy); diff --git a/lib/nlattr.c b/lib/nlattr.c index c4706eb98d3..00e8a02681a 100644 --- a/lib/nlattr.c +++ b/lib/nlattr.c @@ -15,7 +15,7 @@ #include #include -static u16 nla_attr_minlen[NLA_TYPE_MAX+1] __read_mostly = { +static const u16 nla_attr_minlen[NLA_TYPE_MAX+1] = { [NLA_U8] = sizeof(u8), [NLA_U16] = sizeof(u16), [NLA_U32] = sizeof(u32), @@ -23,7 +23,7 @@ static u16 nla_attr_minlen[NLA_TYPE_MAX+1] __read_mostly = { [NLA_NESTED] = NLA_HDRLEN, }; -static int validate_nla(struct nlattr *nla, int maxtype, +static int validate_nla(const struct nlattr *nla, int maxtype, const struct nla_policy *policy) { const struct nla_policy *pt; @@ -115,10 +115,10 @@ static int validate_nla(struct nlattr *nla, int maxtype, * * Returns 0 on success or a negative error code. */ -int nla_validate(struct nlattr *head, int len, int maxtype, +int nla_validate(const struct nlattr *head, int len, int maxtype, const struct nla_policy *policy) { - struct nlattr *nla; + const struct nlattr *nla; int rem, err; nla_for_each_attr(nla, head, len, rem) { @@ -173,10 +173,10 @@ nla_policy_len(const struct nla_policy *p, int n) * * 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) +int nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head, + int len, const struct nla_policy *policy) { - struct nlattr *nla; + const struct nlattr *nla; int rem, err; memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1)); @@ -191,7 +191,7 @@ int nla_parse(struct nlattr *tb[], int maxtype, struct nlattr *head, int len, goto errout; } - tb[type] = nla; + tb[type] = (struct nlattr *)nla; } } @@ -212,14 +212,14 @@ errout: * * 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_find(const struct nlattr *head, int len, int attrtype) { - struct nlattr *nla; + const struct nlattr *nla; int rem; nla_for_each_attr(nla, head, len, rem) if (nla_type(nla) == attrtype) - return nla; + return (struct nlattr *)nla; return NULL; } -- 2.39.3