From 7d9dbdfbfdc5e52131bea94a7318ee35b15a5f19 Mon Sep 17 00:00:00 2001 From: Menglong Dong Date: Wed, 13 Apr 2022 16:15:58 +0800 Subject: net: ipv6: add skb drop reasons to TLV parse Replace kfree_skb() used in TLV encoded option header parsing with kfree_skb_reason(). Following functions are involved: ip6_parse_tlv() ipv6_hop_ra() ipv6_hop_ioam() ipv6_hop_jumbo() ipv6_hop_calipso() ipv6_dest_hao() Most skb drops during this process are regarded as 'InHdrErrors', as 'IPSTATS_MIB_INHDRERRORS' is used when ip6_parse_tlv() fails, which make we use 'SKB_DROP_REASON_IP_INHDR' correspondingly. However, 'IP_INHDR' is a relatively general reason. Therefore, we can use other reasons with higher priority in some cases. For example, 'SKB_DROP_REASON_UNHANDLED_PROTO' is used for unknown TLV options. Signed-off-by: Menglong Dong Reviewed-by: Jiang Biao Reviewed-by: Hao Peng Signed-off-by: David S. Miller --- net/ipv6/exthdrs.c | 36 ++++++++++++++++++++++++------------ 1 file changed, 24 insertions(+), 12 deletions(-) (limited to 'net/ipv6/exthdrs.c') diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c index 403f8ba76b9f..a8d961d3a477 100644 --- a/net/ipv6/exthdrs.c +++ b/net/ipv6/exthdrs.c @@ -90,12 +90,13 @@ static bool ip6_tlvopt_unknown(struct sk_buff *skb, int optoff, break; fallthrough; case 2: /* send ICMP PARM PROB regardless and drop packet */ - icmpv6_param_prob(skb, ICMPV6_UNK_OPTION, optoff); + icmpv6_param_prob_reason(skb, ICMPV6_UNK_OPTION, optoff, + SKB_DROP_REASON_UNHANDLED_PROTO); return false; } drop: - kfree_skb(skb); + kfree_skb_reason(skb, SKB_DROP_REASON_UNHANDLED_PROTO); return false; } @@ -218,7 +219,7 @@ static bool ip6_parse_tlv(bool hopbyhop, if (len == 0) return true; bad: - kfree_skb(skb); + kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR); return false; } @@ -232,6 +233,7 @@ static bool ipv6_dest_hao(struct sk_buff *skb, int optoff) struct ipv6_destopt_hao *hao; struct inet6_skb_parm *opt = IP6CB(skb); struct ipv6hdr *ipv6h = ipv6_hdr(skb); + SKB_DR(reason); int ret; if (opt->dsthao) { @@ -246,19 +248,23 @@ static bool ipv6_dest_hao(struct sk_buff *skb, int optoff) if (hao->length != 16) { net_dbg_ratelimited("hao invalid option length = %d\n", hao->length); + SKB_DR_SET(reason, IP_INHDR); goto discard; } if (!(ipv6_addr_type(&hao->addr) & IPV6_ADDR_UNICAST)) { net_dbg_ratelimited("hao is not an unicast addr: %pI6\n", &hao->addr); + SKB_DR_SET(reason, INVALID_PROTO); goto discard; } ret = xfrm6_input_addr(skb, (xfrm_address_t *)&ipv6h->daddr, (xfrm_address_t *)&hao->addr, IPPROTO_DSTOPTS); - if (unlikely(ret < 0)) + if (unlikely(ret < 0)) { + SKB_DR_SET(reason, XFRM_POLICY); goto discard; + } if (skb_cloned(skb)) { if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) @@ -281,7 +287,7 @@ static bool ipv6_dest_hao(struct sk_buff *skb, int optoff) return true; discard: - kfree_skb(skb); + kfree_skb_reason(skb, reason); return false; } #endif @@ -931,7 +937,7 @@ static bool ipv6_hop_ra(struct sk_buff *skb, int optoff) } net_dbg_ratelimited("ipv6_hop_ra: wrong RA length %d\n", nh[optoff + 1]); - kfree_skb(skb); + kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR); return false; } @@ -985,7 +991,7 @@ ignore: return true; drop: - kfree_skb(skb); + kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR); return false; } @@ -994,26 +1000,32 @@ drop: static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff) { const unsigned char *nh = skb_network_header(skb); + SKB_DR(reason); u32 pkt_len; if (nh[optoff + 1] != 4 || (optoff & 3) != 2) { net_dbg_ratelimited("ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n", nh[optoff+1]); + SKB_DR_SET(reason, IP_INHDR); goto drop; } pkt_len = ntohl(*(__be32 *)(nh + optoff + 2)); if (pkt_len <= IPV6_MAXPLEN) { - icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff+2); + icmpv6_param_prob_reason(skb, ICMPV6_HDR_FIELD, optoff + 2, + SKB_DROP_REASON_IP_INHDR); return false; } if (ipv6_hdr(skb)->payload_len) { - icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff); + icmpv6_param_prob_reason(skb, ICMPV6_HDR_FIELD, optoff, + SKB_DROP_REASON_IP_INHDR); return false; } - if (pkt_len > skb->len - sizeof(struct ipv6hdr)) + if (pkt_len > skb->len - sizeof(struct ipv6hdr)) { + SKB_DR_SET(reason, PKT_TOO_SMALL); goto drop; + } if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) goto drop; @@ -1022,7 +1034,7 @@ static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff) return true; drop: - kfree_skb(skb); + kfree_skb_reason(skb, reason); return false; } @@ -1044,7 +1056,7 @@ static bool ipv6_hop_calipso(struct sk_buff *skb, int optoff) return true; drop: - kfree_skb(skb); + kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR); return false; } -- cgit v1.2.3