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netfilter: nf_tables: remove skb and nlh from context structure
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Instead of caching the original skbuff that contains the netlink
messages, this stores the netlink message sequence number, the
netlink portID and the report flag. This helps to prepare the
introduction of the object release via call_rcu.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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Pablo Neira Ayuso committed May 19, 2014
1 parent 35151d8 commit 128ad33
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Showing 2 changed files with 52 additions and 59 deletions.
10 changes: 6 additions & 4 deletions include/net/netfilter/nf_tables.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -72,21 +72,23 @@ static inline void nft_data_debug(const struct nft_data *data)
* struct nft_ctx - nf_tables rule/set context
*
* @net: net namespace
* @skb: netlink skb
* @nlh: netlink message header
* @afi: address family info
* @table: the table the chain is contained in
* @chain: the chain the rule is contained in
* @nla: netlink attributes
* @portid: netlink portID of the original message
* @seq: netlink sequence number
* @report: notify via unicast netlink message
*/
struct nft_ctx {
struct net *net;
const struct sk_buff *skb;
const struct nlmsghdr *nlh;
struct nft_af_info *afi;
struct nft_table *table;
struct nft_chain *chain;
const struct nlattr * const *nla;
u32 portid;
u32 seq;
bool report;
};

struct nft_data_desc {
Expand Down
101 changes: 46 additions & 55 deletions net/netfilter/nf_tables_api.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -96,13 +96,14 @@ static void nft_ctx_init(struct nft_ctx *ctx,
struct nft_chain *chain,
const struct nlattr * const *nla)
{
ctx->net = sock_net(skb->sk);
ctx->skb = skb;
ctx->nlh = nlh;
ctx->afi = afi;
ctx->table = table;
ctx->chain = chain;
ctx->nla = nla;
ctx->net = sock_net(skb->sk);
ctx->afi = afi;
ctx->table = table;
ctx->chain = chain;
ctx->nla = nla;
ctx->portid = NETLINK_CB(skb).portid;
ctx->report = nlmsg_report(nlh);
ctx->seq = nlh->nlmsg_seq;
}

static struct nft_trans *nft_trans_alloc(struct nft_ctx *ctx, int msg_type,
Expand Down Expand Up @@ -238,33 +239,31 @@ static int nf_tables_fill_table_info(struct sk_buff *skb, u32 portid, u32 seq,
static int nf_tables_table_notify(const struct nft_ctx *ctx, int event)
{
struct sk_buff *skb;
u32 portid = NETLINK_CB(ctx->skb).portid;
u32 seq = ctx->nlh->nlmsg_seq;
struct net *net = sock_net(ctx->skb->sk);
bool report;
int err;

report = nlmsg_report(ctx->nlh);
if (!report && !nfnetlink_has_listeners(net, NFNLGRP_NFTABLES))
if (!ctx->report &&
!nfnetlink_has_listeners(ctx->net, NFNLGRP_NFTABLES))
return 0;

err = -ENOBUFS;
skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
if (skb == NULL)
goto err;

err = nf_tables_fill_table_info(skb, portid, seq, event, 0,
err = nf_tables_fill_table_info(skb, ctx->portid, ctx->seq, event, 0,
ctx->afi->family, ctx->table);
if (err < 0) {
kfree_skb(skb);
goto err;
}

err = nfnetlink_send(skb, net, portid, NFNLGRP_NFTABLES, report,
GFP_KERNEL);
err = nfnetlink_send(skb, ctx->net, ctx->portid, NFNLGRP_NFTABLES,
ctx->report, GFP_KERNEL);
err:
if (err < 0)
nfnetlink_set_err(net, portid, NFNLGRP_NFTABLES, err);
if (err < 0) {
nfnetlink_set_err(ctx->net, ctx->portid, NFNLGRP_NFTABLES,
err);
}
return err;
}

Expand Down Expand Up @@ -721,34 +720,32 @@ static int nf_tables_fill_chain_info(struct sk_buff *skb, u32 portid, u32 seq,
static int nf_tables_chain_notify(const struct nft_ctx *ctx, int event)
{
struct sk_buff *skb;
u32 portid = NETLINK_CB(ctx->skb).portid;
struct net *net = sock_net(ctx->skb->sk);
u32 seq = ctx->nlh->nlmsg_seq;
bool report;
int err;

report = nlmsg_report(ctx->nlh);
if (!report && !nfnetlink_has_listeners(net, NFNLGRP_NFTABLES))
if (!ctx->report &&
!nfnetlink_has_listeners(ctx->net, NFNLGRP_NFTABLES))
return 0;

err = -ENOBUFS;
skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
if (skb == NULL)
goto err;

err = nf_tables_fill_chain_info(skb, portid, seq, event, 0,
err = nf_tables_fill_chain_info(skb, ctx->portid, ctx->seq, event, 0,
ctx->afi->family, ctx->table,
ctx->chain);
if (err < 0) {
kfree_skb(skb);
goto err;
}

err = nfnetlink_send(skb, net, portid, NFNLGRP_NFTABLES, report,
GFP_KERNEL);
err = nfnetlink_send(skb, ctx->net, ctx->portid, NFNLGRP_NFTABLES,
ctx->report, GFP_KERNEL);
err:
if (err < 0)
nfnetlink_set_err(net, portid, NFNLGRP_NFTABLES, err);
if (err < 0) {
nfnetlink_set_err(ctx->net, ctx->portid, NFNLGRP_NFTABLES,
err);
}
return err;
}

Expand Down Expand Up @@ -1473,36 +1470,33 @@ static int nf_tables_rule_notify(const struct nft_ctx *ctx,
const struct nft_rule *rule,
int event)
{
const struct sk_buff *oskb = ctx->skb;
struct sk_buff *skb;
u32 portid = NETLINK_CB(oskb).portid;
struct net *net = sock_net(oskb->sk);
u32 seq = ctx->nlh->nlmsg_seq;
bool report;
int err;

report = nlmsg_report(ctx->nlh);
if (!report && !nfnetlink_has_listeners(net, NFNLGRP_NFTABLES))
if (!ctx->report &&
!nfnetlink_has_listeners(ctx->net, NFNLGRP_NFTABLES))
return 0;

err = -ENOBUFS;
skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
if (skb == NULL)
goto err;

err = nf_tables_fill_rule_info(skb, portid, seq, event, 0,
err = nf_tables_fill_rule_info(skb, ctx->portid, ctx->seq, event, 0,
ctx->afi->family, ctx->table,
ctx->chain, rule);
if (err < 0) {
kfree_skb(skb);
goto err;
}

err = nfnetlink_send(skb, net, portid, NFNLGRP_NFTABLES, report,
GFP_KERNEL);
err = nfnetlink_send(skb, ctx->net, ctx->portid, NFNLGRP_NFTABLES,
ctx->report, GFP_KERNEL);
err:
if (err < 0)
nfnetlink_set_err(net, portid, NFNLGRP_NFTABLES, err);
if (err < 0) {
nfnetlink_set_err(ctx->net, ctx->portid, NFNLGRP_NFTABLES,
err);
}
return err;
}

Expand Down Expand Up @@ -2141,8 +2135,8 @@ static int nf_tables_fill_set(struct sk_buff *skb, const struct nft_ctx *ctx,
struct nfgenmsg *nfmsg;
struct nlmsghdr *nlh;
struct nlattr *desc;
u32 portid = NETLINK_CB(ctx->skb).portid;
u32 seq = ctx->nlh->nlmsg_seq;
u32 portid = ctx->portid;
u32 seq = ctx->seq;

event |= NFNL_SUBSYS_NFTABLES << 8;
nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct nfgenmsg),
Expand Down Expand Up @@ -2194,12 +2188,11 @@ static int nf_tables_set_notify(const struct nft_ctx *ctx,
int event)
{
struct sk_buff *skb;
u32 portid = NETLINK_CB(ctx->skb).portid;
bool report;
u32 portid = ctx->portid;
int err;

report = nlmsg_report(ctx->nlh);
if (!report && !nfnetlink_has_listeners(ctx->net, NFNLGRP_NFTABLES))
if (!ctx->report &&
!nfnetlink_has_listeners(ctx->net, NFNLGRP_NFTABLES))
return 0;

err = -ENOBUFS;
Expand All @@ -2213,8 +2206,8 @@ static int nf_tables_set_notify(const struct nft_ctx *ctx,
goto err;
}

err = nfnetlink_send(skb, ctx->net, portid, NFNLGRP_NFTABLES, report,
GFP_KERNEL);
err = nfnetlink_send(skb, ctx->net, portid, NFNLGRP_NFTABLES,
ctx->report, GFP_KERNEL);
err:
if (err < 0)
nfnetlink_set_err(ctx->net, portid, NFNLGRP_NFTABLES, err);
Expand Down Expand Up @@ -2956,14 +2949,12 @@ static int nf_tables_setelem_notify(const struct nft_ctx *ctx,
const struct nft_set_elem *elem,
int event, u16 flags)
{
const struct sk_buff *oskb = ctx->skb;
struct net *net = sock_net(oskb->sk);
u32 portid = NETLINK_CB(oskb).portid;
bool report = nlmsg_report(ctx->nlh);
struct net *net = ctx->net;
u32 portid = ctx->portid;
struct sk_buff *skb;
int err;

if (!report && !nfnetlink_has_listeners(net, NFNLGRP_NFTABLES))
if (!ctx->report && !nfnetlink_has_listeners(net, NFNLGRP_NFTABLES))
return 0;

err = -ENOBUFS;
Expand All @@ -2978,7 +2969,7 @@ static int nf_tables_setelem_notify(const struct nft_ctx *ctx,
goto err;
}

err = nfnetlink_send(skb, net, portid, NFNLGRP_NFTABLES, report,
err = nfnetlink_send(skb, net, portid, NFNLGRP_NFTABLES, ctx->report,
GFP_KERNEL);
err:
if (err < 0)
Expand Down

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