Add version option support to the nftables "osf" expression.
Signed-off-by: Fernando Fernandez Mancera <ffmancera@xxxxxxxxxx>
---
v1: initial patch
v2: flags type is now u32 and using snprintf() instead of strlcat()
---
include/linux/netfilter/nfnetlink_osf.h | 11 ++++++---
include/uapi/linux/netfilter/nf_tables.h | 6 +++++
net/netfilter/nfnetlink_osf.c | 14 +++++------
net/netfilter/nft_osf.c | 30 ++++++++++++++++++++----
4 files changed, 46 insertions(+), 15 deletions(-)
diff --git a/include/linux/netfilter/nfnetlink_osf.h b/include/linux/netfilter/nfnetlink_osf.h
index c6000046c966..788613f36935 100644
--- a/include/linux/netfilter/nfnetlink_osf.h
+++ b/include/linux/netfilter/nfnetlink_osf.h
@@ -21,13 +21,18 @@ struct nf_osf_finger {
struct nf_osf_user_finger finger;
};
+struct nf_osf_data {
+ const char *genre;
+ const char *version;
+};
+
bool nf_osf_match(const struct sk_buff *skb, u_int8_t family,
int hooknum, struct net_device *in, struct net_device *out,
const struct nf_osf_info *info, struct net *net,
const struct list_head *nf_osf_fingers);
-const char *nf_osf_find(const struct sk_buff *skb,
- const struct list_head *nf_osf_fingers,
- const int ttl_check);
+bool nf_osf_find(const struct sk_buff *skb,
+ const struct list_head *nf_osf_fingers,
+ const int ttl_check, struct nf_osf_data *data);
#endif /* _NFOSF_H */
diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h
index a66c8de006cc..061bb3eb20c3 100644
--- a/include/uapi/linux/netfilter/nf_tables.h
+++ b/include/uapi/linux/netfilter/nf_tables.h
@@ -1522,15 +1522,21 @@ enum nft_flowtable_hook_attributes {
*
* @NFTA_OSF_DREG: destination register (NLA_U32: nft_registers)
* @NFTA_OSF_TTL: Value of the TTL osf option (NLA_U8)
+ * @NFTA_OSF_FLAGS: flags (NLA_U32)
*/
enum nft_osf_attributes {
NFTA_OSF_UNSPEC,
NFTA_OSF_DREG,
NFTA_OSF_TTL,
+ NFTA_OSF_FLAGS,
__NFTA_OSF_MAX,
};
#define NFTA_OSF_MAX (__NFTA_OSF_MAX - 1)
+enum nft_osf_flags {
+ NFT_OSF_F_VERSION = (1 << 0),
+};
+
/**
* enum nft_device_attributes - nf_tables device netlink attributes
*
diff --git a/net/netfilter/nfnetlink_osf.c b/net/netfilter/nfnetlink_osf.c
index 1f1d90c1716b..7b827bcb412c 100644
--- a/net/netfilter/nfnetlink_osf.c
+++ b/net/netfilter/nfnetlink_osf.c
@@ -255,9 +255,9 @@ nf_osf_match(const struct sk_buff *skb, u_int8_t family,
}
EXPORT_SYMBOL_GPL(nf_osf_match);
-const char *nf_osf_find(const struct sk_buff *skb,
- const struct list_head *nf_osf_fingers,
- const int ttl_check)
+bool nf_osf_find(const struct sk_buff *skb,
+ const struct list_head *nf_osf_fingers,
+ const int ttl_check, struct nf_osf_data *data)
{
const struct iphdr *ip = ip_hdr(skb);
const struct nf_osf_user_finger *f;
@@ -265,24 +265,24 @@ const char *nf_osf_find(const struct sk_buff *skb,
const struct nf_osf_finger *kf;
struct nf_osf_hdr_ctx ctx;
const struct tcphdr *tcp;
- const char *genre = NULL;
memset(&ctx, 0, sizeof(ctx));
tcp = nf_osf_hdr_ctx_init(&ctx, skb, ip, opts);
if (!tcp)
- return NULL;
+ return false;
list_for_each_entry_rcu(kf, &nf_osf_fingers[ctx.df], finger_entry) {
f = &kf->finger;
if (!nf_osf_match_one(skb, f, ttl_check, &ctx))
continue;
- genre = f->genre;
+ data->genre = f->genre;
+ data->version = f->version;
break;
}
- return genre;
+ return true;
}
EXPORT_SYMBOL_GPL(nf_osf_find);
diff --git a/net/netfilter/nft_osf.c b/net/netfilter/nft_osf.c
index b13618c764ec..87b60d6617ef 100644
--- a/net/netfilter/nft_osf.c
+++ b/net/netfilter/nft_osf.c
@@ -7,11 +7,13 @@
struct nft_osf {
enum nft_registers dreg:8;
u8 ttl;
+ u32 flags;
};
static const struct nla_policy nft_osf_policy[NFTA_OSF_MAX + 1] = {
[NFTA_OSF_DREG] = { .type = NLA_U32 },
[NFTA_OSF_TTL] = { .type = NLA_U8 },
+ [NFTA_OSF_FLAGS] = { .type = NLA_U32 },
};
static void nft_osf_eval(const struct nft_expr *expr, struct nft_regs *regs,
@@ -20,9 +22,10 @@ static void nft_osf_eval(const struct nft_expr *expr, struct nft_regs *regs,
struct nft_osf *priv = nft_expr_priv(expr);
u32 *dest = ®s->data[priv->dreg];
struct sk_buff *skb = pkt->skb;
+ char os_match[NFT_OSF_MAXGENRELEN + 1];
const struct tcphdr *tcp;
+ struct nf_osf_data data;
struct tcphdr _tcph;
- const char *os_name;
tcp = skb_header_pointer(skb, ip_hdrlen(skb),
sizeof(struct tcphdr), &_tcph);
@@ -35,11 +38,17 @@ static void nft_osf_eval(const struct nft_expr *expr, struct nft_regs *regs,
return;
}
- os_name = nf_osf_find(skb, nf_osf_fingers, priv->ttl);
- if (!os_name)
+ if (!nf_osf_find(skb, nf_osf_fingers, priv->ttl, &data)) {
strncpy((char *)dest, "unknown", NFT_OSF_MAXGENRELEN);
- else
- strncpy((char *)dest, os_name, NFT_OSF_MAXGENRELEN);
+ } else {
+ if (priv->flags & NFT_OSF_F_VERSION)
+ snprintf(os_match, NFT_OSF_MAXGENRELEN, "%s:%s",
+ data.genre, data.version);
+ else
+ strlcpy(os_match, data.genre, NFT_OSF_MAXGENRELEN);
+
+ strncpy((char *)dest, os_match, NFT_OSF_MAXGENRELEN);
+ }
}
static int nft_osf_init(const struct nft_ctx *ctx,
@@ -47,6 +56,7 @@ static int nft_osf_init(const struct nft_ctx *ctx,
const struct nlattr * const tb[])
{
struct nft_osf *priv = nft_expr_priv(expr);
+ u32 flags;
int err;
u8 ttl;
@@ -57,6 +67,13 @@ static int nft_osf_init(const struct nft_ctx *ctx,
priv->ttl = ttl;
}
+ if (tb[NFTA_OSF_FLAGS]) {
+ flags = ntohl(nla_get_be32(tb[NFTA_OSF_FLAGS]));
+ if (flags != NFT_OSF_F_VERSION)
+ return -EINVAL;
+ priv->flags = flags;
+ }
+
priv->dreg = nft_parse_register(tb[NFTA_OSF_DREG]);
err = nft_validate_register_store(ctx, priv->dreg, NULL,
NFT_DATA_VALUE, NFT_OSF_MAXGENRELEN);
@@ -73,6 +90,9 @@ static int nft_osf_dump(struct sk_buff *skb, const struct nft_expr *expr)
if (nla_put_u8(skb, NFTA_OSF_TTL, priv->ttl))
goto nla_put_failure;
+ if (nla_put_be32(skb, NFTA_OSF_FLAGS, ntohl(priv->flags)))
+ goto nla_put_failure;
+
if (nft_dump_register(skb, NFTA_OSF_DREG, priv->dreg))
goto nla_put_failure;
--
2.20.1
