| Message ID | 20160905083655.GA15395@sonyv |
|---|---|
| State | Changes Requested |
| Delegated to: | Pablo Neira |
| Headers | show |
On Mon, Sep 05, 2016 at 10:36:57AM +0200, Laura Garcia Liebana wrote: > Add support to pass through an offset to the hash value. With this > feature, the sysadmin is able to generate a hash with a given > offset value. > > Example: > > meta mark set jhash ip saddr mod 2 seed 0xabcd sum 100 > > This option generates marks according to the source address from 100 to > 101. > > Signed-off-by: Laura Garcia Liebana <nevola@gmail.com> > --- > include/uapi/linux/netfilter/nf_tables.h | 2 ++ > net/netfilter/nft_hash.c | 13 +++++++++++-- > 2 files changed, 13 insertions(+), 2 deletions(-) > > diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h > index 4dbeeed..8026684 100644 > --- a/include/uapi/linux/netfilter/nf_tables.h > +++ b/include/uapi/linux/netfilter/nf_tables.h > @@ -764,6 +764,7 @@ enum nft_meta_keys { > * @NFTA_HASH_LEN: source data length (NLA_U32) > * @NFTA_HASH_MODULUS: modulus value (NLA_U32) > * @NFTA_HASH_SEED: seed value (NLA_U32) > + * @NFTA_HASH_SUM: Hash offset value (NLA_U32) > */ > enum nft_hash_attributes { > NFTA_HASH_UNSPEC, > @@ -772,6 +773,7 @@ enum nft_hash_attributes { > NFTA_HASH_LEN, > NFTA_HASH_MODULUS, > NFTA_HASH_SEED, > + NFTA_HASH_SUM, > __NFTA_HASH_MAX, > }; > #define NFTA_HASH_MAX (__NFTA_HASH_MAX - 1) > diff --git a/net/netfilter/nft_hash.c b/net/netfilter/nft_hash.c > index b7e3b40..8ab04d9 100644 > --- a/net/netfilter/nft_hash.c > +++ b/net/netfilter/nft_hash.c > @@ -23,6 +23,7 @@ struct nft_hash { > u8 len; > u32 modulus; > u32 seed; > + u32 sum; > }; > > static void nft_hash_eval(const struct nft_expr *expr, > @@ -35,7 +36,7 @@ static void nft_hash_eval(const struct nft_expr *expr, > > h = reciprocal_scale(jhash(data, priv->len, priv->seed), priv->modulus); > > - regs->data[priv->dreg] = h; > + regs->data[priv->dreg] = priv->sum + h; > } > > const struct nla_policy nft_hash_policy[NFTA_HASH_MAX + 1] = { > @@ -44,6 +45,7 @@ const struct nla_policy nft_hash_policy[NFTA_HASH_MAX + 1] = { > [NFTA_HASH_LEN] = { .type = NLA_U32 }, > [NFTA_HASH_MODULUS] = { .type = NLA_U32 }, > [NFTA_HASH_SEED] = { .type = NLA_U32 }, > + [NFTA_HASH_SUM] = { .type = NLA_U32 }, > }; > > static int nft_hash_init(const struct nft_ctx *ctx, > @@ -60,6 +62,11 @@ static int nft_hash_init(const struct nft_ctx *ctx, > !tb[NFTA_HASH_MODULUS]) > return -EINVAL; > > + if (tb[NFTA_HASH_SUM]) > + priv->sum = ntohl(nla_get_be32(tb[NFTA_HASH_SUM])); > + else > + priv->sum = 0; There is a corner case that we should reject from the kernel, I think this is: if (priv->sum + priv->modulus - 1 < priv->sum) return -EOVERFLOW; We'll handle this from userspace anyway too, but I think it's easy to reject this crazy this. -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Sep 05, 2016 at 11:10:28AM +0200, Pablo Neira Ayuso wrote: > On Mon, Sep 05, 2016 at 10:36:57AM +0200, Laura Garcia Liebana wrote: > > Add support to pass through an offset to the hash value. With this > > feature, the sysadmin is able to generate a hash with a given > > offset value. > > > > Example: > > > > meta mark set jhash ip saddr mod 2 seed 0xabcd sum 100 > > > > This option generates marks according to the source address from 100 to > > 101. > > > > Signed-off-by: Laura Garcia Liebana <nevola@gmail.com> > > --- > > include/uapi/linux/netfilter/nf_tables.h | 2 ++ > > net/netfilter/nft_hash.c | 13 +++++++++++-- > > 2 files changed, 13 insertions(+), 2 deletions(-) > > > > diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h > > index 4dbeeed..8026684 100644 > > --- a/include/uapi/linux/netfilter/nf_tables.h > > +++ b/include/uapi/linux/netfilter/nf_tables.h > > @@ -764,6 +764,7 @@ enum nft_meta_keys { > > * @NFTA_HASH_LEN: source data length (NLA_U32) > > * @NFTA_HASH_MODULUS: modulus value (NLA_U32) > > * @NFTA_HASH_SEED: seed value (NLA_U32) > > + * @NFTA_HASH_SUM: Hash offset value (NLA_U32) > > */ > > enum nft_hash_attributes { > > NFTA_HASH_UNSPEC, > > @@ -772,6 +773,7 @@ enum nft_hash_attributes { > > NFTA_HASH_LEN, > > NFTA_HASH_MODULUS, > > NFTA_HASH_SEED, > > + NFTA_HASH_SUM, > > __NFTA_HASH_MAX, > > }; > > #define NFTA_HASH_MAX (__NFTA_HASH_MAX - 1) > > diff --git a/net/netfilter/nft_hash.c b/net/netfilter/nft_hash.c > > index b7e3b40..8ab04d9 100644 > > --- a/net/netfilter/nft_hash.c > > +++ b/net/netfilter/nft_hash.c > > @@ -23,6 +23,7 @@ struct nft_hash { > > u8 len; > > u32 modulus; > > u32 seed; > > + u32 sum; > > }; > > > > static void nft_hash_eval(const struct nft_expr *expr, > > @@ -35,7 +36,7 @@ static void nft_hash_eval(const struct nft_expr *expr, > > > > h = reciprocal_scale(jhash(data, priv->len, priv->seed), priv->modulus); > > > > - regs->data[priv->dreg] = h; > > + regs->data[priv->dreg] = priv->sum + h; > > } > > > > const struct nla_policy nft_hash_policy[NFTA_HASH_MAX + 1] = { > > @@ -44,6 +45,7 @@ const struct nla_policy nft_hash_policy[NFTA_HASH_MAX + 1] = { > > [NFTA_HASH_LEN] = { .type = NLA_U32 }, > > [NFTA_HASH_MODULUS] = { .type = NLA_U32 }, > > [NFTA_HASH_SEED] = { .type = NLA_U32 }, > > + [NFTA_HASH_SUM] = { .type = NLA_U32 }, > > }; > > > > static int nft_hash_init(const struct nft_ctx *ctx, > > @@ -60,6 +62,11 @@ static int nft_hash_init(const struct nft_ctx *ctx, > > !tb[NFTA_HASH_MODULUS]) > > return -EINVAL; > > > > + if (tb[NFTA_HASH_SUM]) > > + priv->sum = ntohl(nla_get_be32(tb[NFTA_HASH_SUM])); > > + else > > + priv->sum = 0; > > There is a corner case that we should reject from the kernel, I think > this is: > > if (priv->sum + priv->modulus - 1 < priv->sum) > return -EOVERFLOW; > > We'll handle this from userspace anyway too, but I think it's easy to > reject this crazy this. Such case shouldn't happen cause the modulus must be > 1. The init() provides: priv->modulus = ntohl(nla_get_be32(tb[NFTA_HASH_MODULUS])); if (priv->modulus <= 1) return -ERANGE; -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Sep 05, 2016 at 11:58:24AM +0200, Laura Garcia wrote: > On Mon, Sep 05, 2016 at 11:10:28AM +0200, Pablo Neira Ayuso wrote: > > On Mon, Sep 05, 2016 at 10:36:57AM +0200, Laura Garcia Liebana wrote: > > > Add support to pass through an offset to the hash value. With this > > > feature, the sysadmin is able to generate a hash with a given > > > offset value. > > > > > > Example: > > > > > > meta mark set jhash ip saddr mod 2 seed 0xabcd sum 100 > > > > > > This option generates marks according to the source address from 100 to > > > 101. > > > > > > Signed-off-by: Laura Garcia Liebana <nevola@gmail.com> > > > --- > > > include/uapi/linux/netfilter/nf_tables.h | 2 ++ > > > net/netfilter/nft_hash.c | 13 +++++++++++-- > > > 2 files changed, 13 insertions(+), 2 deletions(-) > > > > > > diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h > > > index 4dbeeed..8026684 100644 > > > --- a/include/uapi/linux/netfilter/nf_tables.h > > > +++ b/include/uapi/linux/netfilter/nf_tables.h > > > @@ -764,6 +764,7 @@ enum nft_meta_keys { > > > * @NFTA_HASH_LEN: source data length (NLA_U32) > > > * @NFTA_HASH_MODULUS: modulus value (NLA_U32) > > > * @NFTA_HASH_SEED: seed value (NLA_U32) > > > + * @NFTA_HASH_SUM: Hash offset value (NLA_U32) > > > */ > > > enum nft_hash_attributes { > > > NFTA_HASH_UNSPEC, > > > @@ -772,6 +773,7 @@ enum nft_hash_attributes { > > > NFTA_HASH_LEN, > > > NFTA_HASH_MODULUS, > > > NFTA_HASH_SEED, > > > + NFTA_HASH_SUM, > > > __NFTA_HASH_MAX, > > > }; > > > #define NFTA_HASH_MAX (__NFTA_HASH_MAX - 1) > > > diff --git a/net/netfilter/nft_hash.c b/net/netfilter/nft_hash.c > > > index b7e3b40..8ab04d9 100644 > > > --- a/net/netfilter/nft_hash.c > > > +++ b/net/netfilter/nft_hash.c > > > @@ -23,6 +23,7 @@ struct nft_hash { > > > u8 len; > > > u32 modulus; > > > u32 seed; > > > + u32 sum; > > > }; > > > > > > static void nft_hash_eval(const struct nft_expr *expr, > > > @@ -35,7 +36,7 @@ static void nft_hash_eval(const struct nft_expr *expr, > > > > > > h = reciprocal_scale(jhash(data, priv->len, priv->seed), priv->modulus); > > > > > > - regs->data[priv->dreg] = h; > > > + regs->data[priv->dreg] = priv->sum + h; > > > } > > > > > > const struct nla_policy nft_hash_policy[NFTA_HASH_MAX + 1] = { > > > @@ -44,6 +45,7 @@ const struct nla_policy nft_hash_policy[NFTA_HASH_MAX + 1] = { > > > [NFTA_HASH_LEN] = { .type = NLA_U32 }, > > > [NFTA_HASH_MODULUS] = { .type = NLA_U32 }, > > > [NFTA_HASH_SEED] = { .type = NLA_U32 }, > > > + [NFTA_HASH_SUM] = { .type = NLA_U32 }, > > > }; > > > > > > static int nft_hash_init(const struct nft_ctx *ctx, > > > @@ -60,6 +62,11 @@ static int nft_hash_init(const struct nft_ctx *ctx, > > > !tb[NFTA_HASH_MODULUS]) > > > return -EINVAL; > > > > > > + if (tb[NFTA_HASH_SUM]) > > > + priv->sum = ntohl(nla_get_be32(tb[NFTA_HASH_SUM])); > > > + else > > > + priv->sum = 0; > > > > There is a corner case that we should reject from the kernel, I think > > this is: > > > > if (priv->sum + priv->modulus - 1 < priv->sum) > > return -EOVERFLOW; > > > > We'll handle this from userspace anyway too, but I think it's easy to > > reject this crazy this. > > Such case shouldn't happen cause the modulus must be > 1. The init() > provides: > > priv->modulus = ntohl(nla_get_be32(tb[NFTA_HASH_MODULUS])); > if (priv->modulus <= 1) > return -ERANGE; I don't see how this is preventing an overflow of hash(x) + sum. -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h index 4dbeeed..8026684 100644 --- a/include/uapi/linux/netfilter/nf_tables.h +++ b/include/uapi/linux/netfilter/nf_tables.h @@ -764,6 +764,7 @@ enum nft_meta_keys { * @NFTA_HASH_LEN: source data length (NLA_U32) * @NFTA_HASH_MODULUS: modulus value (NLA_U32) * @NFTA_HASH_SEED: seed value (NLA_U32) + * @NFTA_HASH_SUM: Hash offset value (NLA_U32) */ enum nft_hash_attributes { NFTA_HASH_UNSPEC, @@ -772,6 +773,7 @@ enum nft_hash_attributes { NFTA_HASH_LEN, NFTA_HASH_MODULUS, NFTA_HASH_SEED, + NFTA_HASH_SUM, __NFTA_HASH_MAX, }; #define NFTA_HASH_MAX (__NFTA_HASH_MAX - 1) diff --git a/net/netfilter/nft_hash.c b/net/netfilter/nft_hash.c index b7e3b40..8ab04d9 100644 --- a/net/netfilter/nft_hash.c +++ b/net/netfilter/nft_hash.c @@ -23,6 +23,7 @@ struct nft_hash { u8 len; u32 modulus; u32 seed; + u32 sum; }; static void nft_hash_eval(const struct nft_expr *expr, @@ -35,7 +36,7 @@ static void nft_hash_eval(const struct nft_expr *expr, h = reciprocal_scale(jhash(data, priv->len, priv->seed), priv->modulus); - regs->data[priv->dreg] = h; + regs->data[priv->dreg] = priv->sum + h; } const struct nla_policy nft_hash_policy[NFTA_HASH_MAX + 1] = { @@ -44,6 +45,7 @@ const struct nla_policy nft_hash_policy[NFTA_HASH_MAX + 1] = { [NFTA_HASH_LEN] = { .type = NLA_U32 }, [NFTA_HASH_MODULUS] = { .type = NLA_U32 }, [NFTA_HASH_SEED] = { .type = NLA_U32 }, + [NFTA_HASH_SUM] = { .type = NLA_U32 }, }; static int nft_hash_init(const struct nft_ctx *ctx, @@ -60,6 +62,11 @@ static int nft_hash_init(const struct nft_ctx *ctx, !tb[NFTA_HASH_MODULUS]) return -EINVAL; + if (tb[NFTA_HASH_SUM]) + priv->sum = ntohl(nla_get_be32(tb[NFTA_HASH_SUM])); + else + priv->sum = 0; + priv->sreg = nft_parse_register(tb[NFTA_HASH_SREG]); if (priv->sreg < 0) return -ERANGE; @@ -99,7 +106,9 @@ static int nft_hash_dump(struct sk_buff *skb, goto nla_put_failure; if (nft_dump_register(skb, NFTA_HASH_SEED, priv->seed)) goto nla_put_failure; - + if (priv->sum != 0) + if (nft_dump_register(skb, NFTA_HASH_SUM, priv->sum)) + goto nla_put_failure; return 0; nla_put_failure:
Add support to pass through an offset to the hash value. With this feature, the sysadmin is able to generate a hash with a given offset value. Example: meta mark set jhash ip saddr mod 2 seed 0xabcd sum 100 This option generates marks according to the source address from 100 to 101. Signed-off-by: Laura Garcia Liebana <nevola@gmail.com> --- include/uapi/linux/netfilter/nf_tables.h | 2 ++ net/netfilter/nft_hash.c | 13 +++++++++++-- 2 files changed, 13 insertions(+), 2 deletions(-)