From 73e3b002fb9086fc734ba4dcc3041f9bb56eb1a2 Mon Sep 17 00:00:00 2001 From: Menglong Dong Date: Mon, 30 May 2022 16:12:00 +0800 Subject: [PATCH] net: skb: use auto-generation to convert skb drop reason to string It is annoying to add new skb drop reasons to 'enum skb_drop_reason' and TRACE_SKB_DROP_REASON in trace/event/skb.h, and it's easy to forget to add the new reasons we added to TRACE_SKB_DROP_REASON. TRACE_SKB_DROP_REASON is used to convert drop reason of type number to string. For now, the string we passed to user space is exactly the same as the name in 'enum skb_drop_reason' with a 'SKB_DROP_REASON_' prefix. Therefore, we can use 'auto-generation' to generate these drop reasons to string at build time. The new header 'dropreason_str.h' will be generated, and the __DEFINE_SKB_DROP_REASON() in it can do the converting job. Meanwhile, we use a global array to store these string, which can be used both in drop_monitor and 'kfree_skb' tracepoint. Signed-off-by: Menglong Dong --- include/net/dropreason.h | 4 ++ include/trace/events/skb.h | 89 +------------------------------------- net/core/.gitignore | 1 + net/core/Makefile | 23 +++++++++- net/core/drop_monitor.c | 13 ------ 5 files changed, 28 insertions(+), 102 deletions(-) create mode 100644 net/core/.gitignore diff --git a/include/net/dropreason.h b/include/net/dropreason.h index ecd18b7b1364a9..460de425297c11 100644 --- a/include/net/dropreason.h +++ b/include/net/dropreason.h @@ -3,6 +3,8 @@ #ifndef _LINUX_DROPREASON_H #define _LINUX_DROPREASON_H +#include + /* The reason of skb drop, which is used in kfree_skb_reason(). * en...maybe they should be splited by group? * @@ -181,4 +183,6 @@ enum skb_drop_reason { SKB_DR_SET(name, reason); \ } while (0) +extern const char * const drop_reasons[]; + #endif diff --git a/include/trace/events/skb.h b/include/trace/events/skb.h index a477bf9074982c..45264e4bb254f7 100644 --- a/include/trace/events/skb.h +++ b/include/trace/events/skb.h @@ -9,92 +9,6 @@ #include #include -#define TRACE_SKB_DROP_REASON \ - EM(SKB_DROP_REASON_NOT_SPECIFIED, NOT_SPECIFIED) \ - EM(SKB_DROP_REASON_NO_SOCKET, NO_SOCKET) \ - EM(SKB_DROP_REASON_PKT_TOO_SMALL, PKT_TOO_SMALL) \ - EM(SKB_DROP_REASON_TCP_CSUM, TCP_CSUM) \ - EM(SKB_DROP_REASON_SOCKET_FILTER, SOCKET_FILTER) \ - EM(SKB_DROP_REASON_UDP_CSUM, UDP_CSUM) \ - EM(SKB_DROP_REASON_NETFILTER_DROP, NETFILTER_DROP) \ - EM(SKB_DROP_REASON_OTHERHOST, OTHERHOST) \ - EM(SKB_DROP_REASON_IP_CSUM, IP_CSUM) \ - EM(SKB_DROP_REASON_IP_INHDR, IP_INHDR) \ - EM(SKB_DROP_REASON_IP_RPFILTER, IP_RPFILTER) \ - EM(SKB_DROP_REASON_UNICAST_IN_L2_MULTICAST, \ - UNICAST_IN_L2_MULTICAST) \ - EM(SKB_DROP_REASON_XFRM_POLICY, XFRM_POLICY) \ - EM(SKB_DROP_REASON_IP_NOPROTO, IP_NOPROTO) \ - EM(SKB_DROP_REASON_SOCKET_RCVBUFF, SOCKET_RCVBUFF) \ - EM(SKB_DROP_REASON_PROTO_MEM, PROTO_MEM) \ - EM(SKB_DROP_REASON_TCP_MD5NOTFOUND, TCP_MD5NOTFOUND) \ - EM(SKB_DROP_REASON_TCP_MD5UNEXPECTED, \ - TCP_MD5UNEXPECTED) \ - EM(SKB_DROP_REASON_TCP_MD5FAILURE, TCP_MD5FAILURE) \ - EM(SKB_DROP_REASON_SOCKET_BACKLOG, SOCKET_BACKLOG) \ - EM(SKB_DROP_REASON_TCP_FLAGS, TCP_FLAGS) \ - EM(SKB_DROP_REASON_TCP_ZEROWINDOW, TCP_ZEROWINDOW) \ - EM(SKB_DROP_REASON_TCP_OLD_DATA, TCP_OLD_DATA) \ - EM(SKB_DROP_REASON_TCP_OVERWINDOW, TCP_OVERWINDOW) \ - EM(SKB_DROP_REASON_TCP_OFOMERGE, TCP_OFOMERGE) \ - EM(SKB_DROP_REASON_TCP_OFO_DROP, TCP_OFO_DROP) \ - EM(SKB_DROP_REASON_TCP_RFC7323_PAWS, TCP_RFC7323_PAWS) \ - EM(SKB_DROP_REASON_TCP_INVALID_SEQUENCE, \ - TCP_INVALID_SEQUENCE) \ - EM(SKB_DROP_REASON_TCP_RESET, TCP_RESET) \ - EM(SKB_DROP_REASON_TCP_INVALID_SYN, TCP_INVALID_SYN) \ - EM(SKB_DROP_REASON_TCP_CLOSE, TCP_CLOSE) \ - EM(SKB_DROP_REASON_TCP_FASTOPEN, TCP_FASTOPEN) \ - EM(SKB_DROP_REASON_TCP_OLD_ACK, TCP_OLD_ACK) \ - EM(SKB_DROP_REASON_TCP_TOO_OLD_ACK, TCP_TOO_OLD_ACK) \ - EM(SKB_DROP_REASON_TCP_ACK_UNSENT_DATA, \ - TCP_ACK_UNSENT_DATA) \ - EM(SKB_DROP_REASON_TCP_OFO_QUEUE_PRUNE, \ - TCP_OFO_QUEUE_PRUNE) \ - EM(SKB_DROP_REASON_IP_OUTNOROUTES, IP_OUTNOROUTES) \ - EM(SKB_DROP_REASON_BPF_CGROUP_EGRESS, \ - BPF_CGROUP_EGRESS) \ - EM(SKB_DROP_REASON_IPV6DISABLED, IPV6DISABLED) \ - EM(SKB_DROP_REASON_NEIGH_CREATEFAIL, NEIGH_CREATEFAIL) \ - EM(SKB_DROP_REASON_NEIGH_FAILED, NEIGH_FAILED) \ - EM(SKB_DROP_REASON_NEIGH_QUEUEFULL, NEIGH_QUEUEFULL) \ - EM(SKB_DROP_REASON_NEIGH_DEAD, NEIGH_DEAD) \ - EM(SKB_DROP_REASON_TC_EGRESS, TC_EGRESS) \ - EM(SKB_DROP_REASON_QDISC_DROP, QDISC_DROP) \ - EM(SKB_DROP_REASON_CPU_BACKLOG, CPU_BACKLOG) \ - EM(SKB_DROP_REASON_XDP, XDP) \ - EM(SKB_DROP_REASON_TC_INGRESS, TC_INGRESS) \ - EM(SKB_DROP_REASON_UNHANDLED_PROTO, UNHANDLED_PROTO) \ - EM(SKB_DROP_REASON_SKB_CSUM, SKB_CSUM) \ - EM(SKB_DROP_REASON_SKB_GSO_SEG, SKB_GSO_SEG) \ - EM(SKB_DROP_REASON_SKB_UCOPY_FAULT, SKB_UCOPY_FAULT) \ - EM(SKB_DROP_REASON_DEV_HDR, DEV_HDR) \ - EM(SKB_DROP_REASON_DEV_READY, DEV_READY) \ - EM(SKB_DROP_REASON_FULL_RING, FULL_RING) \ - EM(SKB_DROP_REASON_NOMEM, NOMEM) \ - EM(SKB_DROP_REASON_HDR_TRUNC, HDR_TRUNC) \ - EM(SKB_DROP_REASON_TAP_FILTER, TAP_FILTER) \ - 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) \ - EM(SKB_DROP_REASON_PKT_TOO_BIG, PKT_TOO_BIG) \ - EMe(SKB_DROP_REASON_MAX, MAX) - -#undef EM -#undef EMe - -#define EM(a, b) TRACE_DEFINE_ENUM(a); -#define EMe(a, b) TRACE_DEFINE_ENUM(a); - -TRACE_SKB_DROP_REASON - -#undef EM -#undef EMe -#define EM(a, b) { a, #b }, -#define EMe(a, b) { a, #b } - /* * Tracepoint for free an sk_buff: */ @@ -121,8 +35,7 @@ TRACE_EVENT(kfree_skb, TP_printk("skbaddr=%p protocol=%u location=%p reason: %s", __entry->skbaddr, __entry->protocol, __entry->location, - __print_symbolic(__entry->reason, - TRACE_SKB_DROP_REASON)) + drop_reasons[__entry->reason]) ); TRACE_EVENT(consume_skb, diff --git a/net/core/.gitignore b/net/core/.gitignore new file mode 100644 index 00000000000000..104e3001078587 --- /dev/null +++ b/net/core/.gitignore @@ -0,0 +1 @@ +dropreason_str.c \ No newline at end of file diff --git a/net/core/Makefile b/net/core/Makefile index a8e4f737692bb8..3c7f99ff6d892b 100644 --- a/net/core/Makefile +++ b/net/core/Makefile @@ -4,7 +4,8 @@ # obj-y := sock.o request_sock.o skbuff.o datagram.o stream.o scm.o \ - gen_stats.o gen_estimator.o net_namespace.o secure_seq.o flow_dissector.o + gen_stats.o gen_estimator.o net_namespace.o secure_seq.o \ + flow_dissector.o dropreason_str.o obj-$(CONFIG_SYSCTL) += sysctl_net_core.o @@ -39,3 +40,23 @@ obj-$(CONFIG_NET_SOCK_MSG) += skmsg.o obj-$(CONFIG_BPF_SYSCALL) += sock_map.o obj-$(CONFIG_BPF_SYSCALL) += bpf_sk_storage.o obj-$(CONFIG_OF) += of_net.o + +clean-files := dropreason_str.c + +quiet_cmd_dropreason_str = GEN $@ +cmd_dropreason_str = awk -F ',' 'BEGIN{ print "\#include \n"; \ + print "const char * const drop_reasons[] = {" }\ + /^enum skb_drop/ { dr=1; }\ + /\}\;/ { dr=0; }\ + /^\tSKB_DROP_REASON_/ {\ + if (dr) {\ + sub(/\tSKB_DROP_REASON_/, "", $$1);\ + printf "\t[SKB_DROP_REASON_%s] = \"%s\",\n", $$1, $$1;\ + }\ + } \ + END{ print "};\nEXPORT_SYMBOL(drop_reasons);" }' $< > $@ + +$(obj)/dropreason_str.c: $(srctree)/include/net/dropreason.h + $(call cmd,dropreason_str) + +$(obj)/dropreason_str.o: $(obj)/dropreason_str.c diff --git a/net/core/drop_monitor.c b/net/core/drop_monitor.c index 41cac0e4834e82..4ad1decce72418 100644 --- a/net/core/drop_monitor.c +++ b/net/core/drop_monitor.c @@ -48,19 +48,6 @@ static int trace_state = TRACE_OFF; static bool monitor_hw; -#undef EM -#undef EMe - -#define EM(a, b) [a] = #b, -#define EMe(a, b) [a] = #b - -/* drop_reasons is used to translate 'enum skb_drop_reason' to string, - * which is reported to user space. - */ -static const char * const drop_reasons[] = { - TRACE_SKB_DROP_REASON -}; - /* net_dm_mutex * * An overall lock guarding every operation coming from userspace.