From a13fbf5ed5b4fc9095f12e955ca3a59b5507ff01 Mon Sep 17 00:00:00 2001 From: Xin Long Date: Sat, 28 Jan 2023 10:58:34 -0500 Subject: [PATCH] netfilter: use skb_ip_totlen and iph_totlen There are also quite some places in netfilter that may process IPv4 TCP GSO packets, we need to replace them too. In length_mt(), we have to use u_int32_t/int to accept skb_ip_totlen() return value, otherwise it may overflow and mismatch. This change will also help us add selftest for IPv4 BIG TCP in the following patch. Note that we don't need to replace the one in tcpmss_tg4(), as it will return if there is data after tcphdr in tcpmss_mangle_packet(). The same in mangle_contents() in nf_nat_helper.c, it returns false when skb->len + extra > 65535 in enlarge_skb(). Signed-off-by: Xin Long Reviewed-by: Eric Dumazet Signed-off-by: Jakub Kicinski --- include/net/netfilter/nf_tables_ipv4.h | 4 ++-- net/netfilter/ipvs/ip_vs_xmit.c | 2 +- net/netfilter/nf_log_syslog.c | 2 +- net/netfilter/xt_length.c | 2 +- 4 files changed, 5 insertions(+), 5 deletions(-) diff --git a/include/net/netfilter/nf_tables_ipv4.h b/include/net/netfilter/nf_tables_ipv4.h index 112708f7a6b4..947973623dc7 100644 --- a/include/net/netfilter/nf_tables_ipv4.h +++ b/include/net/netfilter/nf_tables_ipv4.h @@ -29,7 +29,7 @@ static inline int __nft_set_pktinfo_ipv4_validate(struct nft_pktinfo *pkt) if (iph->ihl < 5 || iph->version != 4) return -1; - len = ntohs(iph->tot_len); + len = iph_totlen(pkt->skb, iph); thoff = iph->ihl * 4; if (pkt->skb->len < len) return -1; @@ -64,7 +64,7 @@ static inline int nft_set_pktinfo_ipv4_ingress(struct nft_pktinfo *pkt) if (iph->ihl < 5 || iph->version != 4) goto inhdr_error; - len = ntohs(iph->tot_len); + len = iph_totlen(pkt->skb, iph); thoff = iph->ihl * 4; if (pkt->skb->len < len) { __IP_INC_STATS(nft_net(pkt), IPSTATS_MIB_INTRUNCATEDPKTS); diff --git a/net/netfilter/ipvs/ip_vs_xmit.c b/net/netfilter/ipvs/ip_vs_xmit.c index 029171379884..80448885c3d7 100644 --- a/net/netfilter/ipvs/ip_vs_xmit.c +++ b/net/netfilter/ipvs/ip_vs_xmit.c @@ -994,7 +994,7 @@ ip_vs_prepare_tunneled_skb(struct sk_buff *skb, int skb_af, old_dsfield = ipv4_get_dsfield(old_iph); *ttl = old_iph->ttl; if (payload_len) - *payload_len = ntohs(old_iph->tot_len); + *payload_len = skb_ip_totlen(skb); } /* Implement full-functionality option for ECN encapsulation */ diff --git a/net/netfilter/nf_log_syslog.c b/net/netfilter/nf_log_syslog.c index cb894f0d63e9..c66689ad2b49 100644 --- a/net/netfilter/nf_log_syslog.c +++ b/net/netfilter/nf_log_syslog.c @@ -322,7 +322,7 @@ dump_ipv4_packet(struct net *net, struct nf_log_buf *m, /* Max length: 46 "LEN=65535 TOS=0xFF PREC=0xFF TTL=255 ID=65535 " */ nf_log_buf_add(m, "LEN=%u TOS=0x%02X PREC=0x%02X TTL=%u ID=%u ", - ntohs(ih->tot_len), ih->tos & IPTOS_TOS_MASK, + iph_totlen(skb, ih), ih->tos & IPTOS_TOS_MASK, ih->tos & IPTOS_PREC_MASK, ih->ttl, ntohs(ih->id)); /* Max length: 6 "CE DF MF " */ diff --git a/net/netfilter/xt_length.c b/net/netfilter/xt_length.c index 1873da3a945a..b3d623a52885 100644 --- a/net/netfilter/xt_length.c +++ b/net/netfilter/xt_length.c @@ -21,7 +21,7 @@ static bool length_mt(const struct sk_buff *skb, struct xt_action_param *par) { const struct xt_length_info *info = par->matchinfo; - u_int16_t pktlen = ntohs(ip_hdr(skb)->tot_len); + u32 pktlen = skb_ip_totlen(skb); return (pktlen >= info->min && pktlen <= info->max) ^ info->invert; }