Messages in this thread | | | Date | Wed, 21 Feb 2024 13:20:02 +0300 | Subject | Re: [PATCH net-next v1] net: ipv6: hop tlv ext hdr parsing | From | Denis Kirjanov <> |
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On 2/21/24 13:03, Richard Gobert wrote: > This patch introduces 'hop_tlv_hdr' and 'hop_calipso_hdr' structs, in > order to access fields in a readable way in "ip6_parse_tlv". > > Signed-off-by: Richard Gobert <richardbgobert@gmail.com> > --- > include/net/ipv6.h | 16 ++++++++++++++++ > net/ipv6/exthdrs.c | 30 +++++++++++++++++------------- > 2 files changed, 33 insertions(+), 13 deletions(-) > > diff --git a/include/net/ipv6.h b/include/net/ipv6.h > index cf25ea21d770..61677946ed46 100644 > --- a/include/net/ipv6.h > +++ b/include/net/ipv6.h > @@ -151,6 +151,22 @@ struct frag_hdr { > __be32 identification; > }; > > +struct hop_tlv_hdr { > + u8 tlv_type; > + u8 tlv_len; > +}; > + > +/* CALIPSO RFC 5570 */ > +struct hop_calipso_hdr { > + u8 tlv_type; > + u8 tlv_len; > + u32 domain_interpretation; > + u8 cmpt_len; > + u8 sens_lvl; > + u16 checksum; > + u64 cmpt_bitmap; > +} __packed; > + > /* > * Jumbo payload option, as described in RFC 2675 2. > */ > diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c > index 4952ae792450..5db624299da4 100644 > --- a/net/ipv6/exthdrs.c > +++ b/net/ipv6/exthdrs.c > @@ -114,7 +114,7 @@ static bool ip6_parse_tlv(bool hopbyhop, > struct sk_buff *skb, > int max_count) > { > - int len = (skb_transport_header(skb)[1] + 1) << 3; > + int len = ipv6_optlen((struct ipv6_opt_hdr *)skb_transport_header(skb)); > const unsigned char *nh = skb_network_header(skb); > int off = skb_network_header_len(skb); > bool disallow_unknowns = false; > @@ -890,15 +890,16 @@ static inline struct net *ipv6_skb_net(struct sk_buff *skb) > > static bool ipv6_hop_ra(struct sk_buff *skb, int optoff) > { > - const unsigned char *nh = skb_network_header(skb); > + struct hop_tlv_hdr *tlv_hdr = You've forgotten to contstify your struct here and below
> + (struct hop_tlv_hdr *)(skb_network_header(skb) + optoff); > > - if (nh[optoff + 1] == 2) { > + if (tlv_hdr->tlv_len == 2) { > IP6CB(skb)->flags |= IP6SKB_ROUTERALERT; > - memcpy(&IP6CB(skb)->ra, nh + optoff + 2, sizeof(IP6CB(skb)->ra)); > + memcpy(&IP6CB(skb)->ra, tlv_hdr + 1, sizeof(IP6CB(skb)->ra)); > return true; > } > net_dbg_ratelimited("ipv6_hop_ra: wrong RA length %d\n", > - nh[optoff + 1]); > + tlv_hdr->tlv_len); > kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR); > return false; > } > @@ -961,18 +962,20 @@ static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff) > > static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff) > { > - const unsigned char *nh = skb_network_header(skb); > + int tlv_off = offsetof(struct hop_jumbo_hdr, tlv_type); > + struct hop_jumbo_hdr *jumbo_hdr = (struct hop_jumbo_hdr *)
> + (skb_network_header(skb) + optoff - tlv_off); > SKB_DR(reason); > u32 pkt_len; > > - if (nh[optoff + 1] != 4 || (optoff & 3) != 2) { > + if (jumbo_hdr->tlv_len != 4 || (optoff & 3) != 2) { > net_dbg_ratelimited("ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n", > - nh[optoff+1]); > + jumbo_hdr->tlv_len); > SKB_DR_SET(reason, IP_INHDR); > goto drop; > } > > - pkt_len = ntohl(*(__be32 *)(nh + optoff + 2)); > + pkt_len = ntohl(jumbo_hdr->jumbo_payload_len); > if (pkt_len <= IPV6_MAXPLEN) { > icmpv6_param_prob_reason(skb, ICMPV6_HDR_FIELD, optoff + 2, > SKB_DROP_REASON_IP_INHDR); > @@ -1004,15 +1007,16 @@ static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff) > > static bool ipv6_hop_calipso(struct sk_buff *skb, int optoff) > { > - const unsigned char *nh = skb_network_header(skb); > + struct hop_calipso_hdr *calipso_hdr = > + (struct hop_calipso_hdr *)(skb_network_header(skb) + optoff); > > - if (nh[optoff + 1] < 8) > + if (calipso_hdr->tlv_len < 8) > goto drop; > > - if (nh[optoff + 6] * 4 + 8 > nh[optoff + 1]) > + if (calipso_hdr->cmpt_len * 4 + 8 > calipso_hdr->tlv_len) > goto drop; > > - if (!calipso_validate(skb, nh + optoff)) > + if (!calipso_validate(skb, (const unsigned char *)calipso_hdr)) > goto drop; > > return true;
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