Re: [PATCH lttng-modules] Add UDP and ICMP packet header information to the tracepoint:

[Mathieu Desnoyers <mathieu.desnoyers@efficios.com>]

----- On Nov 12, 2019, at 11:39 AM, Florian Walbroel walbroel@silexica.com wrote:

> * UDP transport header
> * ICMP transport header

Hi! Thanks for submitting this patch!

One nit: I suspect the code style needs to be fixed for the switch/case.

Your code appears to have:

switch (cond) {
<tab>case A: ...
}

whereas the coding style should be:

switch (cond) {
case A: ...
}

Can you send an updated patch please ?

Thanks!

Mathieu

> 
> Signed-off-by: Florian Walbroel <walbroel@silexica.com>
> ---
> instrumentation/events/lttng-module/net.h | 172 ++++++++++++++++++++--
> 1 file changed, 156 insertions(+), 16 deletions(-)
> 
> diff --git a/instrumentation/events/lttng-module/net.h
> b/instrumentation/events/lttng-module/net.h
> index 7dd6895..535d0da 100644
> --- a/instrumentation/events/lttng-module/net.h
> +++ b/instrumentation/events/lttng-module/net.h
> @@ -11,6 +11,8 @@
> #include <linux/ip.h>
> #include <linux/ipv6.h>
> #include <linux/tcp.h>
> +#include <linux/udp.h>
> +#include <linux/icmp.h>
> #include <linux/version.h>
> #include <lttng-endian.h>
> #include <net/sock.h>
> @@ -85,6 +87,53 @@ static struct lttng_event_field tcpfields[] = {
> 	},
> };
> 
> +static struct lttng_event_field udpfields[] = {
> +	[0] = {
> +		.name = "source_port",
> +		.type = __type_integer(uint16_t, 0, 0, 0,
> +				__BIG_ENDIAN, 10, none),
> +	},
> +	[1] = {
> +		.name = "dest_port",
> +		.type = __type_integer(uint16_t, 0, 0, 0,
> +				__BIG_ENDIAN, 10, none),
> +	},
> +	[2] = {
> +		.name = "len",
> +		.type = __type_integer(uint16_t, 0, 0, 0,
> +				__BIG_ENDIAN, 10, none),
> +	},
> +	[3] = {
> +		.name = "check",
> +		.type = __type_integer(uint16_t, 0, 0, 0,
> +				__BIG_ENDIAN, 10, none),
> +	},
> +};
> +
> +static struct lttng_event_field icmpfields[] = {
> +	[0] = {
> +		.name = "type",
> +		.type = __type_integer(uint8_t, 0, 0, 0,
> +				__BIG_ENDIAN, 10, none),
> +	},
> +	[1] = {
> +		.name = "code",
> +		.type = __type_integer(uint8_t, 0, 0, 0,
> +				__BIG_ENDIAN, 10, none),
> +	},
> +	[2] = {
> +		.name = "checksum",
> +		.type = __type_integer(uint16_t, 0, 0, 0,
> +				__BIG_ENDIAN, 10, none),
> +	},
> +	[3] = {
> +		.name = "gateway",
> +		.type = __type_integer(uint32_t, 0, 0, 0,
> +				__BIG_ENDIAN, 10, none),
> +	},
> +};
> +
> +
> static struct lttng_event_field transport_fields[] = {
> 	[0] = {
> 		.name = "unknown",
> @@ -102,13 +151,57 @@ static struct lttng_event_field transport_fields[] = {
> 			.u._struct.fields = tcpfields,
> 		},
> 	},
> +	[2] = {
> +		.name = "udp",
> +		.type = {
> +			.atype = atype_struct,
> +			.u._struct.nr_fields = ARRAY_SIZE(udpfields),
> +			.u._struct.fields = udpfields,
> +		},
> +	},
> +	[3] = {
> +		.name = "icmp",
> +		.type = {
> +			.atype = atype_struct,
> +			.u._struct.nr_fields = ARRAY_SIZE(icmpfields),
> +			.u._struct.fields = icmpfields,
> +		},
> +	},
> };
> 
> enum transport_header_types {
> 	TH_NONE = 0,
> 	TH_TCP = 1,
> +	TH_UDP = 2,
> +	TH_ICMP = 3,
> };
> 
> +static inline enum transport_header_types __get_transport_header_type_ip(struct
> sk_buff *skb)
> +{
> +	switch(ip_hdr(skb)->protocol) {
> +		case IPPROTO_TCP:
> +			return TH_TCP;
> +		case IPPROTO_UDP:
> +			return TH_UDP;
> +		case IPPROTO_ICMP:
> +			return TH_ICMP;
> +	}
> +	return TH_NONE;
> +}
> +
> +static inline enum transport_header_types
> __get_transport_header_type_ipv6(struct sk_buff *skb)
> +{
> +	switch(ipv6_hdr(skb)->nexthdr) {
> +		case IPPROTO_TCP:
> +			return TH_TCP;
> +		case IPPROTO_UDP:
> +			return TH_UDP;
> +		case IPPROTO_ICMP:
> +			return TH_ICMP;
> +	}
> +	return TH_NONE;
> +}
> +
> static inline enum transport_header_types __get_transport_header_type(struct
> sk_buff *skb)
> {
> 	if (__has_network_hdr(skb)) {
> @@ -123,13 +216,13 @@ static inline enum transport_header_types
> __get_transport_header_type(struct sk_
> 			 * header's data. This method works both for
> 			 * sent and received packets.
> 			 */
> -			if ((skb->protocol == htons(ETH_P_IP) &&
> -					ip_hdr(skb)->protocol == IPPROTO_TCP) ||
> -				(skb->protocol == htons(ETH_P_IPV6) &&
> -					ipv6_hdr(skb)->nexthdr == IPPROTO_TCP))
> -				return TH_TCP;
> +			if (skb->protocol == htons(ETH_P_IP)) {
> +				return __get_transport_header_type_ip(skb);
> +			} else if(skb->protocol == htons(ETH_P_IPV6)) {
> +				return __get_transport_header_type_ipv6(skb);
> +			}
> 		}
> -		/* Fallthrough for other cases where header is not TCP. */
> +		/* Fallthrough for other cases where header is not recognized. */
> 	}
> 	return TH_NONE;
> }
> @@ -137,16 +230,36 @@ static inline enum transport_header_types
> __get_transport_header_type(struct sk_
> static struct lttng_enum_entry proto_transport_enum_entries[] = {
> 	[0] = {
> 		.start = { .value = 0, .signedness = 0, },
> -		.end = { .value = IPPROTO_TCP - 1, .signedness = 0, },
> +		.end = { .value = IPPROTO_ICMP - 1, .signedness = 0, },
> 		.string = "_unknown",
> 	},
> 	[1] = {
> +		.start = { .value = IPPROTO_ICMP, .signedness = 0, },
> +		.end = { .value = IPPROTO_ICMP, .signedness = 0, },
> +		.string = "_icmp",
> +	},
> +	[2] = {
> +		.start = { .value = IPPROTO_ICMP + 1, .signedness = 0, },
> +		.end = { .value = IPPROTO_TCP - 1, .signedness = 0, },
> +		.string = "_unknown",
> +	},
> +	[3] = {
> 		.start = { .value = IPPROTO_TCP, .signedness = 0, },
> 		.end = { .value = IPPROTO_TCP, .signedness = 0, },
> 		.string = "_tcp",
> 	},
> -	[2] = {
> +	[4] = {
> 		.start = { .value = IPPROTO_TCP + 1, .signedness = 0, },
> +		.end = { .value = IPPROTO_UDP - 1, .signedness = 0, },
> +		.string = "_unknown",
> +	},
> +	[5] = {
> +		.start = { .value = IPPROTO_UDP, .signedness = 0, },
> +		.end = { .value = IPPROTO_UDP, .signedness = 0, },
> +		.string = "_udp",
> +	},
> +	[6] = {
> +		.start = { .value = IPPROTO_UDP + 1, .signedness = 0, },
> 		.end = { .value = 255, .signedness = 0, },
> 		.string = "_unknown",
> 	},
> @@ -169,6 +282,16 @@ static struct lttng_enum_entry transport_enum_entries[] = {
> 		.end = { .value = TH_TCP, .signedness = 0, },
> 		.string = "_tcp",
> 	},
> +	[2] = {
> +		.start = { .value = TH_UDP, .signedness = 0, },
> +		.end = { .value = TH_UDP, .signedness = 0, },
> +		.string = "_udp",
> +	},
> +	[3] = {
> +		.start = { .value = TH_ICMP, .signedness = 0, },
> +		.end = { .value = TH_ICMP, .signedness = 0, },
> +		.string = "_icmp",
> +	},
> };
> 
> static const struct lttng_enum_desc transport_header_type = {
> @@ -510,15 +633,32 @@ LTTNG_TRACEPOINT_EVENT_CLASS(net_dev_template,
> 					ctf_integer_type(unsigned char, th_type)
> 
> 					/* Copy the transport header. */
> -					if (th_type == TH_TCP) {
> -						ctf_align(uint32_t)
> -						ctf_array_type(uint8_t, tcp_hdr(skb),
> -								sizeof(struct tcphdr))
> +					switch (th_type) {
> +						case TH_TCP: {
> +							ctf_align(uint32_t)
> +							ctf_array_type(uint8_t, tcp_hdr(skb),
> +									sizeof(struct tcphdr))
> +							break;
> +						}
> +						case TH_UDP: {
> +							ctf_align(uint32_t)
> +							ctf_array_type(uint8_t, udp_hdr(skb),
> +									sizeof(struct udphdr))
> +							break;
> +						}
> +						case TH_ICMP: {
> +							ctf_align(uint32_t)
> +							ctf_array_type(uint8_t, icmp_hdr(skb),
> +									sizeof(struct udphdr))
> +							break;
> +						}
> +						default:
> +							/*
> +							* For any other transport header type,
> +							* there is nothing to do.
> +							*/
> +							break;
> 					}
> -					/*
> -					 * For any other transport header type,
> -					 * there is nothing to do.
> -					 */
> 				}
> 			)
> 		)
> --
> 2.17.1
> 
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-- 
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com