Re: [PATCH nf-next v2] nft_osf: Add ttl option support
On Thu, Oct 04, 2018 at 01:05:42PM +0200, Fernando Fernandez Mancera wrote: [...] > On 10/3/18 5:36 PM, Pablo Neira Ayuso wrote: [...] > > Better make this optional, ie. > > > > if (tb[NFTA_OSF_TTL]) { > > ttl = nla_get_u8(tb[NFTA_OSF_TTL]); > > if (ttl > 2) > > return -EINVAL; > > > > priv->ttl = ttl; > > } > > > > Seems fine to me, I am going to do it. > > > What is the good default value for priv->ttl? We were using -1 before > > this patch, but now ttl is u8, while nf_osf_ttl() takes a signed > > value. Better make this s8 instead of u8? > > > > Thanks. > > > > About the default value for priv->ttl, I think we can use 0 instead of -1. > Right now, if priv->ttl is -1 the behaviour established is "-m osf --ttl 0". > What do you think about that? Fine with me. Thanks.
Re: [PATCH nf-next v2] nft_osf: Add ttl option support
On 10/3/18 5:36 PM, Pablo Neira Ayuso wrote: Hi Fernando, A few comments. On Sat, Sep 29, 2018 at 12:18:51PM +0200, Fernando Fernandez Mancera wrote: Add ttl option support to the nftables "osf" expression. [..] if (!os_name) strncpy((char *)dest, "unknown", NFT_OSF_MAXGENRELEN); else @@ -46,6 +50,15 @@ static int nft_osf_init(const struct nft_ctx *ctx, { struct nft_osf *priv = nft_expr_priv(expr); int err; + u8 ttl; + + if (!tb[NFTA_OSF_TTL]) + return -EINVAL; + + ttl = nla_get_u8(tb[NFTA_OSF_TTL]); + if (ttl > 2) + return -EOPNOTSUPP; + priv->ttl = nla_get_u8(tb[NFTA_OSF_TTL]); Better make this optional, ie. if (tb[NFTA_OSF_TTL]) { ttl = nla_get_u8(tb[NFTA_OSF_TTL]); if (ttl > 2) return -EINVAL; priv->ttl = ttl; } Seems fine to me, I am going to do it. What is the good default value for priv->ttl? We were using -1 before this patch, but now ttl is u8, while nf_osf_ttl() takes a signed value. Better make this s8 instead of u8? Thanks. About the default value for priv->ttl, I think we can use 0 instead of -1. Right now, if priv->ttl is -1 the behaviour established is "-m osf --ttl 0". What do you think about that? Thanks.
Re: [PATCH nf-next v2] nft_osf: Add ttl option support
Hi Fernando, A few comments. On Sat, Sep 29, 2018 at 12:18:51PM +0200, Fernando Fernandez Mancera wrote: > Add ttl option support to the nftables "osf" expression. > > Signed-off-by: Fernando Fernandez Mancera > --- > v1: initial patch > v2: code correctness and fix the "~" typo. > --- > include/linux/netfilter/nfnetlink_osf.h | 3 ++- > include/uapi/linux/netfilter/nf_tables.h | 7 +++ > net/netfilter/nfnetlink_osf.c| 5 +++-- > net/netfilter/nft_osf.c | 18 +- > 4 files changed, 29 insertions(+), 4 deletions(-) > > diff --git a/include/linux/netfilter/nfnetlink_osf.h > b/include/linux/netfilter/nfnetlink_osf.h > index ecf7dab81e9e..c646c966 100644 > --- a/include/linux/netfilter/nfnetlink_osf.h > +++ b/include/linux/netfilter/nfnetlink_osf.h > @@ -27,6 +27,7 @@ bool nf_osf_match(const struct sk_buff *skb, u_int8_t > family, > 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 struct list_head *nf_osf_fingers, > + const int ttl_check); > > #endif /* _NFOSF_H */ > diff --git a/include/uapi/linux/netfilter/nf_tables.h > b/include/uapi/linux/netfilter/nf_tables.h > index 5444e76870bb..579974b0bf0d 100644 > --- a/include/uapi/linux/netfilter/nf_tables.h > +++ b/include/uapi/linux/netfilter/nf_tables.h > @@ -1511,9 +1511,16 @@ enum nft_flowtable_hook_attributes { > }; > #define NFTA_FLOWTABLE_HOOK_MAX (__NFTA_FLOWTABLE_HOOK_MAX - 1) > > +/** > + * enum nft_osf_attributes - nftables osf expression netlink attributes > + * > + * @NFTA_OSF_DREG: destination register (NLA_U32: nft_registers) > + * @NFTA_OSF_TTL: Value of the TTL osf option (NLA_U8) > + */ > enum nft_osf_attributes { > NFTA_OSF_UNSPEC, > NFTA_OSF_DREG, > + NFTA_OSF_TTL, > __NFTA_OSF_MAX, > }; > #define NFTA_OSF_MAX (__NFTA_OSF_MAX - 1) > diff --git a/net/netfilter/nfnetlink_osf.c b/net/netfilter/nfnetlink_osf.c > index 00db27dfd2ff..ec8fa9661538 100644 > --- a/net/netfilter/nfnetlink_osf.c > +++ b/net/netfilter/nfnetlink_osf.c > @@ -257,7 +257,8 @@ 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 struct list_head *nf_osf_fingers, > + const int ttl_check) > { > const struct iphdr *ip = ip_hdr(skb); > const struct nf_osf_user_finger *f; > @@ -275,7 +276,7 @@ const char *nf_osf_find(const struct sk_buff *skb, > > list_for_each_entry_rcu(kf, _osf_fingers[ctx.df], finger_entry) { > f = >finger; > - if (!nf_osf_match_one(skb, f, -1, )) > + if (!nf_osf_match_one(skb, f, ttl_check, )) > continue; > > genre = f->genre; > diff --git a/net/netfilter/nft_osf.c b/net/netfilter/nft_osf.c > index 5af74b37f423..0fbaaafff8d8 100644 > --- a/net/netfilter/nft_osf.c > +++ b/net/netfilter/nft_osf.c > @@ -6,10 +6,12 @@ > > struct nft_osf { > enum nft_registers dreg:8; > + u8 ttl; > }; > > static const struct nla_policy nft_osf_policy[NFTA_OSF_MAX + 1] = { > [NFTA_OSF_DREG] = { .type = NLA_U32 }, > + [NFTA_OSF_TTL] = { .type = NLA_U8 }, > }; > > static void nft_osf_eval(const struct nft_expr *expr, struct nft_regs *regs, > @@ -21,6 +23,7 @@ static void nft_osf_eval(const struct nft_expr *expr, > struct nft_regs *regs, > const struct tcphdr *tcp; > struct tcphdr _tcph; > const char *os_name; > + int ttl_check; > > tcp = skb_header_pointer(skb, ip_hdrlen(skb), >sizeof(struct tcphdr), &_tcph); > @@ -33,7 +36,8 @@ static void nft_osf_eval(const struct nft_expr *expr, > struct nft_regs *regs, > return; > } > > - os_name = nf_osf_find(skb, nf_osf_fingers); > + ttl_check = priv->ttl; > + os_name = nf_osf_find(skb, nf_osf_fingers, ttl_check); This should be fine, so we don't need the extra 'ttl_check' variable: os_name = nf_osf_find(skb, nf_osf_fingers, priv->ttl); See more comments below. > if (!os_name) > strncpy((char *)dest, "unknown", NFT_OSF_MAXGENRELEN); > else > @@ -46,6 +50,15 @@ static int nft_osf_init(const struct nft_ctx *ctx, > { > struct nft_osf *priv = nft_expr_priv(expr); > int err; > + u8 ttl; > + > + if (!tb[NFTA_OSF_TTL]) > + return -EINVAL; > + > + ttl = nla_get_u8(tb[NFTA_OSF_TTL]); > + if (ttl > 2) > + return -EOPNOTSUPP; > + priv->ttl = nla_get_u8(tb[NFTA_OSF_TTL]); Better make this optional, ie. if (tb[NFTA_OSF_TTL]) { ttl = nla_get_u8(tb[NFTA_OSF_TTL]); if (ttl >
[PATCH nf-next v2] nft_osf: Add ttl option support
Add ttl option support to the nftables "osf" expression. Signed-off-by: Fernando Fernandez Mancera --- v1: initial patch v2: code correctness and fix the "~" typo. --- include/linux/netfilter/nfnetlink_osf.h | 3 ++- include/uapi/linux/netfilter/nf_tables.h | 7 +++ net/netfilter/nfnetlink_osf.c| 5 +++-- net/netfilter/nft_osf.c | 18 +- 4 files changed, 29 insertions(+), 4 deletions(-) diff --git a/include/linux/netfilter/nfnetlink_osf.h b/include/linux/netfilter/nfnetlink_osf.h index ecf7dab81e9e..c646c966 100644 --- a/include/linux/netfilter/nfnetlink_osf.h +++ b/include/linux/netfilter/nfnetlink_osf.h @@ -27,6 +27,7 @@ bool nf_osf_match(const struct sk_buff *skb, u_int8_t family, 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 struct list_head *nf_osf_fingers, + const int ttl_check); #endif /* _NFOSF_H */ diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h index 5444e76870bb..579974b0bf0d 100644 --- a/include/uapi/linux/netfilter/nf_tables.h +++ b/include/uapi/linux/netfilter/nf_tables.h @@ -1511,9 +1511,16 @@ enum nft_flowtable_hook_attributes { }; #define NFTA_FLOWTABLE_HOOK_MAX(__NFTA_FLOWTABLE_HOOK_MAX - 1) +/** + * enum nft_osf_attributes - nftables osf expression netlink attributes + * + * @NFTA_OSF_DREG: destination register (NLA_U32: nft_registers) + * @NFTA_OSF_TTL: Value of the TTL osf option (NLA_U8) + */ enum nft_osf_attributes { NFTA_OSF_UNSPEC, NFTA_OSF_DREG, + NFTA_OSF_TTL, __NFTA_OSF_MAX, }; #define NFTA_OSF_MAX (__NFTA_OSF_MAX - 1) diff --git a/net/netfilter/nfnetlink_osf.c b/net/netfilter/nfnetlink_osf.c index 00db27dfd2ff..ec8fa9661538 100644 --- a/net/netfilter/nfnetlink_osf.c +++ b/net/netfilter/nfnetlink_osf.c @@ -257,7 +257,8 @@ 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 struct list_head *nf_osf_fingers, + const int ttl_check) { const struct iphdr *ip = ip_hdr(skb); const struct nf_osf_user_finger *f; @@ -275,7 +276,7 @@ const char *nf_osf_find(const struct sk_buff *skb, list_for_each_entry_rcu(kf, _osf_fingers[ctx.df], finger_entry) { f = >finger; - if (!nf_osf_match_one(skb, f, -1, )) + if (!nf_osf_match_one(skb, f, ttl_check, )) continue; genre = f->genre; diff --git a/net/netfilter/nft_osf.c b/net/netfilter/nft_osf.c index 5af74b37f423..0fbaaafff8d8 100644 --- a/net/netfilter/nft_osf.c +++ b/net/netfilter/nft_osf.c @@ -6,10 +6,12 @@ struct nft_osf { enum nft_registers dreg:8; + u8 ttl; }; static const struct nla_policy nft_osf_policy[NFTA_OSF_MAX + 1] = { [NFTA_OSF_DREG] = { .type = NLA_U32 }, + [NFTA_OSF_TTL] = { .type = NLA_U8 }, }; static void nft_osf_eval(const struct nft_expr *expr, struct nft_regs *regs, @@ -21,6 +23,7 @@ static void nft_osf_eval(const struct nft_expr *expr, struct nft_regs *regs, const struct tcphdr *tcp; struct tcphdr _tcph; const char *os_name; + int ttl_check; tcp = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(struct tcphdr), &_tcph); @@ -33,7 +36,8 @@ static void nft_osf_eval(const struct nft_expr *expr, struct nft_regs *regs, return; } - os_name = nf_osf_find(skb, nf_osf_fingers); + ttl_check = priv->ttl; + os_name = nf_osf_find(skb, nf_osf_fingers, ttl_check); if (!os_name) strncpy((char *)dest, "unknown", NFT_OSF_MAXGENRELEN); else @@ -46,6 +50,15 @@ static int nft_osf_init(const struct nft_ctx *ctx, { struct nft_osf *priv = nft_expr_priv(expr); int err; + u8 ttl; + + if (!tb[NFTA_OSF_TTL]) + return -EINVAL; + + ttl = nla_get_u8(tb[NFTA_OSF_TTL]); + if (ttl > 2) + return -EOPNOTSUPP; + priv->ttl = nla_get_u8(tb[NFTA_OSF_TTL]); priv->dreg = nft_parse_register(tb[NFTA_OSF_DREG]); err = nft_validate_register_store(ctx, priv->dreg, NULL, @@ -60,6 +73,9 @@ static int nft_osf_dump(struct sk_buff *skb, const struct nft_expr *expr) { const struct nft_osf *priv = nft_expr_priv(expr); + if (nla_put_u8(skb, NFTA_OSF_TTL, priv->ttl)) + goto nla_put_failure; + if (nft_dump_register(skb, NFTA_OSF_DREG, priv->dreg)) goto nla_put_failure; -- 2.19.0