From d6d3146ce532268ad0ffd8d92d2b7492898decf1 Mon Sep 17 00:00:00 2001 From: Menglong Dong Date: Wed, 13 Apr 2022 16:15:52 +0800 Subject: skb: add some helpers for skb drop reasons In order to simply the definition and assignment for 'enum skb_drop_reason', introduce some helpers. SKB_DR() is used to define a variable of type 'enum skb_drop_reason' with the 'SKB_DROP_REASON_NOT_SPECIFIED' initial value. SKB_DR_SET() is used to set the value of the variable. Seems it is a little useless? But it makes the code shorter. SKB_DR_OR() is used to set the value of the variable if it is not set yet, which means its value is SKB_DROP_REASON_NOT_SPECIFIED. Signed-off-by: Menglong Dong Reviewed-by: Jiang Biao Reviewed-by: Hao Peng Signed-off-by: David S. Miller --- include/linux/skbuff.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'include/linux') diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 9b81ba497665..0cbd6ada957c 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -450,6 +450,18 @@ enum skb_drop_reason { SKB_DROP_REASON_MAX, }; +#define SKB_DR_INIT(name, reason) \ + enum skb_drop_reason name = SKB_DROP_REASON_##reason +#define SKB_DR(name) \ + SKB_DR_INIT(name, NOT_SPECIFIED) +#define SKB_DR_SET(name, reason) \ + (name = SKB_DROP_REASON_##reason) +#define SKB_DR_OR(name, reason) \ + do { \ + if (name == SKB_DROP_REASON_NOT_SPECIFIED) \ + SKB_DR_SET(name, reason); \ + } while (0) + /* To allow 64K frame to be packed as single skb without frag_list we * require 64K/PAGE_SIZE pages plus 1 additional page to allow for * buffers which do not start on a page boundary. -- cgit v1.2.3 From c4eb664191b4a5ff6856478f903924176697719e Mon Sep 17 00:00:00 2001 From: Menglong Dong Date: Wed, 13 Apr 2022 16:15:53 +0800 Subject: net: ipv4: add skb drop reasons to ip_error() Eventually, I find out the handler function for inputting route lookup fail: ip_error(). The drop reasons we used in ip_error() are almost corresponding to IPSTATS_MIB_*, and following new reasons are introduced: SKB_DROP_REASON_IP_INADDRERRORS SKB_DROP_REASON_IP_INNOROUTES Isn't the name SKB_DROP_REASON_IP_HOSTUNREACH and SKB_DROP_REASON_IP_NETUNREACH more accurate? To make them corresponding to IPSTATS_MIB_*, we keep their name still. Signed-off-by: Menglong Dong Reviewed-by: Jiang Biao Reviewed-by: Hao Peng Signed-off-by: David S. Miller --- include/linux/skbuff.h | 6 ++++++ include/trace/events/skb.h | 2 ++ net/ipv4/route.c | 6 +++++- 3 files changed, 13 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 0cbd6ada957c..886e83ac4b70 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -447,6 +447,12 @@ enum skb_drop_reason { * 2211, such as a broadcasts * ICMP_TIMESTAMP */ + SKB_DROP_REASON_IP_INADDRERRORS, /* host unreachable, corresponding + * to IPSTATS_MIB_INADDRERRORS + */ + SKB_DROP_REASON_IP_INNOROUTES, /* network unreachable, corresponding + * to IPSTATS_MIB_INADDRERRORS + */ SKB_DROP_REASON_MAX, }; diff --git a/include/trace/events/skb.h b/include/trace/events/skb.h index 42647114fffe..0acac7e5a019 100644 --- a/include/trace/events/skb.h +++ b/include/trace/events/skb.h @@ -63,6 +63,8 @@ EM(SKB_DROP_REASON_TAP_TXFILTER, TAP_TXFILTER) \ EM(SKB_DROP_REASON_ICMP_CSUM, ICMP_CSUM) \ EM(SKB_DROP_REASON_INVALID_PROTO, INVALID_PROTO) \ + EM(SKB_DROP_REASON_IP_INADDRERRORS, IP_INADDRERRORS) \ + EM(SKB_DROP_REASON_IP_INNOROUTES, IP_INNOROUTES) \ EMe(SKB_DROP_REASON_MAX, MAX) #undef EM diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 80f96170876c..e839d424b861 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -945,6 +945,7 @@ static int ip_error(struct sk_buff *skb) struct inet_peer *peer; unsigned long now; struct net *net; + SKB_DR(reason); bool send; int code; @@ -964,10 +965,12 @@ static int ip_error(struct sk_buff *skb) if (!IN_DEV_FORWARD(in_dev)) { switch (rt->dst.error) { case EHOSTUNREACH: + SKB_DR_SET(reason, IP_INADDRERRORS); __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS); break; case ENETUNREACH: + SKB_DR_SET(reason, IP_INNOROUTES); __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); break; } @@ -983,6 +986,7 @@ static int ip_error(struct sk_buff *skb) break; case ENETUNREACH: code = ICMP_NET_UNREACH; + SKB_DR_SET(reason, IP_INNOROUTES); __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); break; case EACCES: @@ -1009,7 +1013,7 @@ static int ip_error(struct sk_buff *skb) if (send) icmp_send(skb, ICMP_DEST_UNREACH, code, 0); -out: kfree_skb(skb); +out: kfree_skb_reason(skb, reason); return 0; } -- cgit v1.2.3 From 2edc1a383fda8d2f580216292dfd9daeae691e47 Mon Sep 17 00:00:00 2001 From: Menglong Dong Date: Wed, 13 Apr 2022 16:15:55 +0800 Subject: net: ip: add skb drop reasons to ip forwarding Replace kfree_skb() which is used in ip6_forward() and ip_forward() with kfree_skb_reason(). The new drop reason 'SKB_DROP_REASON_PKT_TOO_BIG' is introduced for the case that the length of the packet exceeds MTU and can't fragment. Signed-off-by: Menglong Dong Reviewed-by: Jiang Biao Reviewed-by: Hao Peng Signed-off-by: David S. Miller --- include/linux/skbuff.h | 3 +++ include/trace/events/skb.h | 1 + net/ipv4/ip_forward.c | 13 ++++++++++--- net/ipv6/ip6_output.c | 9 ++++++--- 4 files changed, 20 insertions(+), 6 deletions(-) (limited to 'include/linux') diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 886e83ac4b70..0ef11df1bc67 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -453,6 +453,9 @@ enum skb_drop_reason { SKB_DROP_REASON_IP_INNOROUTES, /* network unreachable, corresponding * to IPSTATS_MIB_INADDRERRORS */ + SKB_DROP_REASON_PKT_TOO_BIG, /* packet size is too big (maybe exceed + * the MTU) + */ SKB_DROP_REASON_MAX, }; diff --git a/include/trace/events/skb.h b/include/trace/events/skb.h index 0acac7e5a019..2da72a9a5764 100644 --- a/include/trace/events/skb.h +++ b/include/trace/events/skb.h @@ -65,6 +65,7 @@ EM(SKB_DROP_REASON_INVALID_PROTO, INVALID_PROTO) \ EM(SKB_DROP_REASON_IP_INADDRERRORS, IP_INADDRERRORS) \ EM(SKB_DROP_REASON_IP_INNOROUTES, IP_INNOROUTES) \ + EM(SKB_DROP_REASON_PKT_TOO_BIG, PKT_TOO_BIG) \ EMe(SKB_DROP_REASON_MAX, MAX) #undef EM diff --git a/net/ipv4/ip_forward.c b/net/ipv4/ip_forward.c index 92ba3350274b..e3aa436a1bdf 100644 --- a/net/ipv4/ip_forward.c +++ b/net/ipv4/ip_forward.c @@ -90,6 +90,7 @@ int ip_forward(struct sk_buff *skb) struct rtable *rt; /* Route we use */ struct ip_options *opt = &(IPCB(skb)->opt); struct net *net; + SKB_DR(reason); /* that should never happen */ if (skb->pkt_type != PACKET_HOST) @@ -101,8 +102,10 @@ int ip_forward(struct sk_buff *skb) if (skb_warn_if_lro(skb)) goto drop; - if (!xfrm4_policy_check(NULL, XFRM_POLICY_FWD, skb)) + if (!xfrm4_policy_check(NULL, XFRM_POLICY_FWD, skb)) { + SKB_DR_SET(reason, XFRM_POLICY); goto drop; + } if (IPCB(skb)->opt.router_alert && ip_call_ra_chain(skb)) return NET_RX_SUCCESS; @@ -118,8 +121,10 @@ int ip_forward(struct sk_buff *skb) if (ip_hdr(skb)->ttl <= 1) goto too_many_hops; - if (!xfrm4_route_forward(skb)) + if (!xfrm4_route_forward(skb)) { + SKB_DR_SET(reason, XFRM_POLICY); goto drop; + } rt = skb_rtable(skb); @@ -132,6 +137,7 @@ int ip_forward(struct sk_buff *skb) IP_INC_STATS(net, IPSTATS_MIB_FRAGFAILS); icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu)); + SKB_DR_SET(reason, PKT_TOO_BIG); goto drop; } @@ -169,7 +175,8 @@ too_many_hops: /* Tell the sender its packet died... */ __IP_INC_STATS(net, IPSTATS_MIB_INHDRERRORS); icmp_send(skb, ICMP_TIME_EXCEEDED, ICMP_EXC_TTL, 0); + SKB_DR_SET(reason, IP_INHDR); drop: - kfree_skb(skb); + kfree_skb_reason(skb, reason); return NET_RX_DROP; } diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index e23f058166af..3e729cee6486 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -469,6 +469,7 @@ int ip6_forward(struct sk_buff *skb) struct inet6_skb_parm *opt = IP6CB(skb); struct net *net = dev_net(dst->dev); struct inet6_dev *idev; + SKB_DR(reason); u32 mtu; idev = __in6_dev_get_safely(dev_get_by_index_rcu(net, IP6CB(skb)->iif)); @@ -518,7 +519,7 @@ int ip6_forward(struct sk_buff *skb) icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 0); __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); - kfree_skb(skb); + kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR); return -ETIMEDOUT; } @@ -537,6 +538,7 @@ int ip6_forward(struct sk_buff *skb) if (!xfrm6_route_forward(skb)) { __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS); + SKB_DR_SET(reason, XFRM_POLICY); goto drop; } dst = skb_dst(skb); @@ -596,7 +598,7 @@ int ip6_forward(struct sk_buff *skb) __IP6_INC_STATS(net, idev, IPSTATS_MIB_INTOOBIGERRORS); __IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_FRAGFAILS); - kfree_skb(skb); + kfree_skb_reason(skb, SKB_DROP_REASON_PKT_TOO_BIG); return -EMSGSIZE; } @@ -618,8 +620,9 @@ int ip6_forward(struct sk_buff *skb) error: __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); + SKB_DR_SET(reason, IP_INADDRERRORS); drop: - kfree_skb(skb); + kfree_skb_reason(skb, reason); return -EINVAL; } -- cgit v1.2.3 From 1ad6d548e2a452f21bcee4606ee4ec7afcde5f37 Mon Sep 17 00:00:00 2001 From: Menglong Dong Date: Wed, 13 Apr 2022 16:15:56 +0800 Subject: net: icmp: introduce function icmpv6_param_prob_reason() In order to add the skb drop reasons support to icmpv6_param_prob(), introduce the function icmpv6_param_prob_reason() and make icmpv6_param_prob() an inline call to it. This new function will be used in the following patches. Signed-off-by: Menglong Dong Reviewed-by: Jiang Biao Reviewed-by: Hao Peng Signed-off-by: David S. Miller --- include/linux/icmpv6.h | 11 +++++++++-- net/ipv6/icmp.c | 7 ++++--- 2 files changed, 13 insertions(+), 5 deletions(-) (limited to 'include/linux') diff --git a/include/linux/icmpv6.h b/include/linux/icmpv6.h index 9055cb380ee2..db0f4fcfdaf4 100644 --- a/include/linux/icmpv6.h +++ b/include/linux/icmpv6.h @@ -79,8 +79,9 @@ extern int icmpv6_init(void); extern int icmpv6_err_convert(u8 type, u8 code, int *err); extern void icmpv6_cleanup(void); -extern void icmpv6_param_prob(struct sk_buff *skb, - u8 code, int pos); +extern void icmpv6_param_prob_reason(struct sk_buff *skb, + u8 code, int pos, + enum skb_drop_reason reason); struct flowi6; struct in6_addr; @@ -91,6 +92,12 @@ extern void icmpv6_flow_init(struct sock *sk, const struct in6_addr *daddr, int oif); +static inline void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos) +{ + icmpv6_param_prob_reason(skb, code, pos, + SKB_DROP_REASON_NOT_SPECIFIED); +} + static inline bool icmpv6_is_err(int type) { switch (type) { diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c index 01c8003c9fc9..61770220774e 100644 --- a/net/ipv6/icmp.c +++ b/net/ipv6/icmp.c @@ -629,12 +629,13 @@ out_bh_enable: } EXPORT_SYMBOL(icmp6_send); -/* Slightly more convenient version of icmp6_send. +/* Slightly more convenient version of icmp6_send with drop reasons. */ -void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos) +void icmpv6_param_prob_reason(struct sk_buff *skb, u8 code, int pos, + enum skb_drop_reason reason) { icmp6_send(skb, ICMPV6_PARAMPROB, code, pos, NULL, IP6CB(skb)); - kfree_skb(skb); + kfree_skb_reason(skb, reason); } /* Generate icmpv6 with type/code ICMPV6_DEST_UNREACH/ICMPV6_ADDR_UNREACH -- cgit v1.2.3