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[XFRM] user: Move attribute copying code into copy_to_user_state_extra

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Here's a good example of code duplication leading to code rot.  The
notification patch did its own netlink message creation for xfrm states.
It duplicated code that was already in dump_one_state.  Guess what, the
next time (and the time after) when someone updated dump_one_state the
notification path got zilch.

This patch moves that code from dump_one_state to copy_to_user_state_extra
and uses it in xfrm_notify_sa too.  Unfortunately whoever updates this
still needs to update xfrm_sa_len since the notification path wants to
know the exact size for allocation.

At least I've added a comment saying so and if someone still forgest, we'll
have a WARN_ON telling us so.

I also changed the security size calculation to use xfrm_user_sec_ctx since
that's what we actually put into the skb.  However it makes no practical
difference since it has the same size as xfrm_sec_ctx.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Herbert Xu 2007-10-09 13:30:57 -07:00 committed by David S. Miller
parent 658b219e93
commit 68325d3b12
1 changed files with 47 additions and 29 deletions
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76
net/xfrm/xfrm_user.c
View file

@ -483,9 +483,9 @@ struct xfrm_dump_info {
static int copy_sec_ctx(struct xfrm_sec_ctx *s, struct sk_buff *skb)
{
int ctx_size = sizeof(struct xfrm_sec_ctx) + s->ctx_len;
struct xfrm_user_sec_ctx *uctx;
struct nlattr *attr;
int ctx_size = sizeof(*uctx) + s->ctx_len;
attr = nla_reserve(skb, XFRMA_SEC_CTX, ctx_size);
if (attr == NULL)
@ -502,23 +502,11 @@ static int copy_sec_ctx(struct xfrm_sec_ctx *s, struct sk_buff *skb)
return 0;
}
static int dump_one_state(struct xfrm_state *x, int count, void *ptr)
/* Don't change this without updating xfrm_sa_len! */
static int copy_to_user_state_extra(struct xfrm_state *x,
struct xfrm_usersa_info *p,
struct sk_buff *skb)
{
struct xfrm_dump_info *sp = ptr;
struct sk_buff *in_skb = sp->in_skb;
struct sk_buff *skb = sp->out_skb;
struct xfrm_usersa_info *p;
struct nlmsghdr *nlh;
if (sp->this_idx < sp->start_idx)
goto out;
nlh = nlmsg_put(skb, NETLINK_CB(in_skb).pid, sp->nlmsg_seq,
XFRM_MSG_NEWSA, sizeof(*p), sp->nlmsg_flags);
if (nlh == NULL)
return -EMSGSIZE;
p = nlmsg_data(nlh);
copy_to_user_state(x, p);
if (x->aalg)
@ -540,6 +528,35 @@ static int dump_one_state(struct xfrm_state *x, int count, void *ptr)
if (x->lastused)
NLA_PUT_U64(skb, XFRMA_LASTUSED, x->lastused);
return 0;
nla_put_failure:
return -EMSGSIZE;
}
static int dump_one_state(struct xfrm_state *x, int count, void *ptr)
{
struct xfrm_dump_info *sp = ptr;
struct sk_buff *in_skb = sp->in_skb;
struct sk_buff *skb = sp->out_skb;
struct xfrm_usersa_info *p;
struct nlmsghdr *nlh;
int err;
if (sp->this_idx < sp->start_idx)
goto out;
nlh = nlmsg_put(skb, NETLINK_CB(in_skb).pid, sp->nlmsg_seq,
XFRM_MSG_NEWSA, sizeof(*p), sp->nlmsg_flags);
if (nlh == NULL)
return -EMSGSIZE;
p = nlmsg_data(nlh);
err = copy_to_user_state_extra(x, p, skb);
if (err)
goto nla_put_failure;
nlmsg_end(skb, nlh);
out:
sp->this_idx++;
@ -547,7 +564,7 @@ out:
nla_put_failure:
nlmsg_cancel(skb, nlh);
return -EMSGSIZE;
return err;
}
static int xfrm_dump_sa(struct sk_buff *skb, struct netlink_callback *cb)
@ -1973,6 +1990,14 @@ static inline size_t xfrm_sa_len(struct xfrm_state *x)
l += nla_total_size(sizeof(*x->calg));
if (x->encap)
l += nla_total_size(sizeof(*x->encap));
if (x->security)
l += nla_total_size(sizeof(struct xfrm_user_sec_ctx) +
x->security->ctx_len);
if (x->coaddr)
l += nla_total_size(sizeof(*x->coaddr));
/* Must count this as this may become non-zero behind our back. */
l += nla_total_size(sizeof(x->lastused));
return l;
}
@ -2018,23 +2043,16 @@ static int xfrm_notify_sa(struct xfrm_state *x, struct km_event *c)
p = nla_data(attr);
}
copy_to_user_state(x, p);
if (x->aalg)
NLA_PUT(skb, XFRMA_ALG_AUTH, alg_len(x->aalg), x->aalg);
if (x->ealg)
NLA_PUT(skb, XFRMA_ALG_CRYPT, alg_len(x->ealg), x->ealg);
if (x->calg)
NLA_PUT(skb, XFRMA_ALG_COMP, sizeof(*(x->calg)), x->calg);
if (x->encap)
NLA_PUT(skb, XFRMA_ENCAP, sizeof(*x->encap), x->encap);
if (copy_to_user_state_extra(x, p, skb))
goto nla_put_failure;
nlmsg_end(skb, nlh);
return nlmsg_multicast(xfrm_nl, skb, 0, XFRMNLGRP_SA, GFP_ATOMIC);
nla_put_failure:
/* Somebody screwed up with xfrm_sa_len! */
WARN_ON(1);
kfree_skb(skb);
return -1;
}