[PATCH 17/53] netfilter: introduce nft_set_pktinfo_{ipv4, ipv6}_validate()
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STALE3674d
SUPERSEDED
From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: 2016-09-25 23:06:27
Also in:
netfilter-devel
Subsystem:
netfilter, networking [general], the rest · Maintainers:
Pablo Neira Ayuso, Florian Westphal, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Revision v1 of 44 in this series.
Revisions (44)
These functions are extracted from the netdev family, they initialize
the pktinfo structure and validate that the IPv4 and IPv6 headers are
well-formed given that these functions are called from a path where
layer 3 sanitization did not happen yet.
These functions are placed in include/net/netfilter/nf_tables_ipv{4,6}.h
so they can be reused by a follow up patch to use them from the bridge
family too.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
include/net/netfilter/nf_tables_ipv4.h | 42 ++++++++++++++++++
include/net/netfilter/nf_tables_ipv6.h | 49 +++++++++++++++++++++
net/netfilter/nf_tables_netdev.c | 79 +---------------------------------
3 files changed, 93 insertions(+), 77 deletions(-)
diff --git a/include/net/netfilter/nf_tables_ipv4.h b/include/net/netfilter/nf_tables_ipv4.h
index af952f7843ee..968f00b82fb5 100644
--- a/include/net/netfilter/nf_tables_ipv4.h
+++ b/include/net/netfilter/nf_tables_ipv4.h@@ -20,6 +20,48 @@ nft_set_pktinfo_ipv4(struct nft_pktinfo *pkt, pkt->xt.fragoff = ntohs(ip->frag_off) & IP_OFFSET; } +static inline int +__nft_set_pktinfo_ipv4_validate(struct nft_pktinfo *pkt, + struct sk_buff *skb, + const struct nf_hook_state *state) +{ + struct iphdr *iph, _iph; + u32 len, thoff; + + iph = skb_header_pointer(skb, skb_network_offset(skb), sizeof(*iph), + &_iph); + if (!iph) + return -1; + + iph = ip_hdr(skb); + if (iph->ihl < 5 || iph->version != 4) + return -1; + + len = ntohs(iph->tot_len); + thoff = iph->ihl * 4; + if (skb->len < len) + return -1; + else if (len < thoff) + return -1; + + pkt->tprot_set = true; + pkt->tprot = iph->protocol; + pkt->xt.thoff = thoff; + pkt->xt.fragoff = ntohs(iph->frag_off) & IP_OFFSET; + + return 0; +} + +static inline void +nft_set_pktinfo_ipv4_validate(struct nft_pktinfo *pkt, + struct sk_buff *skb, + const struct nf_hook_state *state) +{ + nft_set_pktinfo(pkt, skb, state); + if (__nft_set_pktinfo_ipv4_validate(pkt, skb, state) < 0) + nft_set_pktinfo_proto_unspec(pkt, skb); +} + extern struct nft_af_info nft_af_ipv4; #endif
diff --git a/include/net/netfilter/nf_tables_ipv6.h b/include/net/netfilter/nf_tables_ipv6.h
index 1e0ffd5aea47..39b7b717b540 100644
--- a/include/net/netfilter/nf_tables_ipv6.h
+++ b/include/net/netfilter/nf_tables_ipv6.h@@ -28,6 +28,55 @@ nft_set_pktinfo_ipv6(struct nft_pktinfo *pkt, return 0; } +static inline int +__nft_set_pktinfo_ipv6_validate(struct nft_pktinfo *pkt, + struct sk_buff *skb, + const struct nf_hook_state *state) +{ +#if IS_ENABLED(CONFIG_IPV6) + struct ipv6hdr *ip6h, _ip6h; + unsigned int thoff = 0; + unsigned short frag_off; + int protohdr; + u32 pkt_len; + + ip6h = skb_header_pointer(skb, skb_network_offset(skb), sizeof(*ip6h), + &_ip6h); + if (!ip6h) + return -1; + + if (ip6h->version != 6) + return -1; + + pkt_len = ntohs(ip6h->payload_len); + if (pkt_len + sizeof(*ip6h) > skb->len) + return -1; + + protohdr = ipv6_find_hdr(pkt->skb, &thoff, -1, &frag_off, NULL); + if (protohdr < 0) + return -1; + + pkt->tprot_set = true; + pkt->tprot = protohdr; + pkt->xt.thoff = thoff; + pkt->xt.fragoff = frag_off; + + return 0; +#else + return -1; +#endif +} + +static inline void +nft_set_pktinfo_ipv6_validate(struct nft_pktinfo *pkt, + struct sk_buff *skb, + const struct nf_hook_state *state) +{ + nft_set_pktinfo(pkt, skb, state); + if (__nft_set_pktinfo_ipv6_validate(pkt, skb, state) < 0) + nft_set_pktinfo_proto_unspec(pkt, skb); +} + extern struct nft_af_info nft_af_ipv6; #endif
diff --git a/net/netfilter/nf_tables_netdev.c b/net/netfilter/nf_tables_netdev.c
index 8de502b0c37b..3e5475a833a5 100644
--- a/net/netfilter/nf_tables_netdev.c
+++ b/net/netfilter/nf_tables_netdev.c@@ -15,81 +15,6 @@ #include <net/netfilter/nf_tables_ipv4.h> #include <net/netfilter/nf_tables_ipv6.h> -static inline void -nft_netdev_set_pktinfo_ipv4(struct nft_pktinfo *pkt, - struct sk_buff *skb, - const struct nf_hook_state *state) -{ - struct iphdr *iph, _iph; - u32 len, thoff; - - nft_set_pktinfo(pkt, skb, state); - - iph = skb_header_pointer(skb, skb_network_offset(skb), sizeof(*iph), - &_iph); - if (!iph) - return; - - iph = ip_hdr(skb); - if (iph->ihl < 5 || iph->version != 4) - return; - - len = ntohs(iph->tot_len); - thoff = iph->ihl * 4; - if (skb->len < len) - return; - else if (len < thoff) - return; - - pkt->tprot_set = true; - pkt->tprot = iph->protocol; - pkt->xt.thoff = thoff; - pkt->xt.fragoff = ntohs(iph->frag_off) & IP_OFFSET; -} - -static inline void -__nft_netdev_set_pktinfo_ipv6(struct nft_pktinfo *pkt, - struct sk_buff *skb, - const struct nf_hook_state *state) -{ -#if IS_ENABLED(CONFIG_IPV6) - struct ipv6hdr *ip6h, _ip6h; - unsigned int thoff = 0; - unsigned short frag_off; - int protohdr; - u32 pkt_len; - - ip6h = skb_header_pointer(skb, skb_network_offset(skb), sizeof(*ip6h), - &_ip6h); - if (!ip6h) - return; - - if (ip6h->version != 6) - return; - - pkt_len = ntohs(ip6h->payload_len); - if (pkt_len + sizeof(*ip6h) > skb->len) - return; - - protohdr = ipv6_find_hdr(pkt->skb, &thoff, -1, &frag_off, NULL); - if (protohdr < 0) - return; - - pkt->tprot_set = true; - pkt->tprot = protohdr; - pkt->xt.thoff = thoff; - pkt->xt.fragoff = frag_off; -#endif -} - -static inline void nft_netdev_set_pktinfo_ipv6(struct nft_pktinfo *pkt, - struct sk_buff *skb, - const struct nf_hook_state *state) -{ - nft_set_pktinfo(pkt, skb, state); - __nft_netdev_set_pktinfo_ipv6(pkt, skb, state); -} - static unsigned int nft_do_chain_netdev(void *priv, struct sk_buff *skb, const struct nf_hook_state *state)
@@ -98,10 +23,10 @@ nft_do_chain_netdev(void *priv, struct sk_buff *skb, switch (skb->protocol) { case htons(ETH_P_IP): - nft_netdev_set_pktinfo_ipv4(&pkt, skb, state); + nft_set_pktinfo_ipv4_validate(&pkt, skb, state); break; case htons(ETH_P_IPV6): - nft_netdev_set_pktinfo_ipv6(&pkt, skb, state); + nft_set_pktinfo_ipv6_validate(&pkt, skb, state); break; default: nft_set_pktinfo_unspec(&pkt, skb, state);
--
2.1.4