net: Add IPv4/IPv6 header data to net_* tracepoints

This patch adds an enum field for the type of network header and a variant
field for the details of IPv4 and IPv6 headers. Any other network header is
empty.

Example babeltrace output:

[16:04:07.443810277] (+0.110633000) host0 net_dev_queue: { cpu_id = 0 },
{ skbaddr = 0xFFFF88003D9F4B00, len = 1462, name = "ens3",
  network_header_type = ( "_ipv4" : container = 1 ),
  network_header = { ipv4 = { version = 4, ihl = 5, tos = 0, tot_len = 1448,
    id = 0x0, frag_off = 16384, ttl = 64, protocol = 6, checksum = 0xB04,
    saddr_padding = { }, saddr = [ [0] = 10, [1] = 0, [2] = 10, [3] = 24 ],
    daddr_padding = { }, daddr = [ [0] = 10, [1] = 0, [2] = 12, [3] = 42 ] }
} }
[16:04:10.452192462] (+0.000283214) host0 net_if_receive_skb: { cpu_id = 0 },
{ skbaddr = 0xFFFF88003D9F4900, len = 118, name = "ens3",
  network_header_type = ( "_ipv6" : container = 2 ),
  network_header = { ipv6 = { version = 6, prio = 0, flow_lbl_padding = { },
    flow_lbl = [ [0] = 0x88, [1] = 0x41, [2] = 0x6F ], payload_len = 64,
    nexthdr = 58, hop_limit = 64, saddr_padding = { },
    saddr = [ [0] = 0xFE80, [1] = 0x0, [2] = 0x0, [3] = 0x0, [4] = 0x5054,
              [5] = 0xFF, [6] = 0xFE12, [7] = 0x3456 ],
    daddr_padding = { },
    daddr = [ [0] = 0xFE80, [1] = 0x0, [2] = 0x0, [3] = 0x0, [4] = 0x40C,
              [5] = 0xA9FF, [6] = 0xFEB5, [7] = 0xA75B ] }
} }

Signed-off-by: Geneviève Bastien <gbastien+lttng@versatic.net>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

diff --git a/instrumentation/events/lttng-module/net.h b/instrumentation/events/lttng-module/net.h
index 4f4b817ac4721baaea7dcc9b3d734f0817a57c74..e33959a2efa1a1d30788417027231dcc8af2b530 100644 (file)
--- a/instrumentation/events/lttng-module/net.h
+++ b/instrumentation/events/lttng-module/net.h
@@ -8,7 +8,190 @@
 #include <linux/skbuff.h>
 #include <linux/netdevice.h>
 #include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/tcp.h>
 #include <linux/version.h>
+#include <lttng-endian.h>
+#include <net/sock.h>
+
+#ifndef ONCE_LTTNG_NET_H
+#define ONCE_LTTNG_NET_H
+
+static inline unsigned char __has_network_hdr(struct sk_buff *skb)
+{
+       /*
+        * If the header is not set yet,
+        * the network header will point to the head.
+        */
+       return skb_network_header(skb) != skb->head;
+}
+
+static struct lttng_event_field emptyfields[] = {
+};
+
+/* Structures for network headers. */
+
+static struct lttng_event_field ipv4fields[] = {
+       [0] = {
+               .name = "version",
+               .type = __type_integer(uint8_t, 4, 4, 0, __BIG_ENDIAN, 10, none),
+       },
+       [1] = {
+               .name = "ihl",
+               .type = __type_integer(uint8_t, 4, 4, 0, __BIG_ENDIAN, 10, none),
+       },
+       [2] = {
+               .name = "tos",
+               .type = __type_integer(uint8_t, 0, 0, 0, __BIG_ENDIAN, 10, none),
+       },
+       [3] = {
+               .name = "tot_len",
+               .type = __type_integer(uint16_t, 0, 0, 0, __BIG_ENDIAN, 10, none),
+       },
+       [4] = {
+               .name = "id",
+               .type = __type_integer(uint16_t, 0, 0, 0, __BIG_ENDIAN, 16, none),
+       },
+       [5] = {
+               .name = "frag_off",
+               .type = __type_integer(uint16_t, 0, 0, 0, __BIG_ENDIAN, 10, none),
+       },
+       [6] = {
+               .name = "ttl",
+               .type = __type_integer(uint8_t, 0, 0, 0, __BIG_ENDIAN, 10, none),
+       },
+       [7] = {
+               .name = "protocol",
+               .type = __type_integer(uint8_t, 0, 0, 0, __BIG_ENDIAN, 10, none),
+       },
+       [8] = {
+               .name = "checksum",
+               .type = __type_integer(uint16_t, 0, 0, 0, __BIG_ENDIAN, 16, none),
+       },
+       [9] = {
+               .name = "saddr",
+               .type = {
+                       .atype = atype_array,
+                       .u.array.elem_type = __type_integer(uint8_t, 0, 0, 0, __BIG_ENDIAN, 10, none),
+                       .u.array.length = 4,
+                       .u.array.elem_alignment = lttng_alignof(uint8_t),
+               },
+       },
+       [10] = {
+               .name = "daddr",
+               .type = {
+                       .atype = atype_array,
+                       .u.array.elem_type = __type_integer(uint8_t, 0, 0, 0, __BIG_ENDIAN, 10, none),
+                       .u.array.length = 4,
+                       .u.array.elem_alignment = lttng_alignof(uint8_t),
+               },
+       },
+};
+
+static struct lttng_event_field ipv6fields[] = {
+       [0] = {
+               .name = "version",
+               .type = __type_integer(uint8_t, 4, 4, 0, __BIG_ENDIAN, 10, none),
+       },
+       [1] = {
+               .name = "prio",
+               .type = __type_integer(uint8_t, 4, 4, 0, __BIG_ENDIAN, 10, none),
+       },
+       [2] = {
+               .name = "flow_lbl",
+               .type = {
+                       .atype = atype_array,
+                       .u.array.elem_type = __type_integer(uint8_t, 0, 0, 0, __BIG_ENDIAN, 16, none),
+                       .u.array.length = 3,
+                       .u.array.elem_alignment = lttng_alignof(uint8_t),
+               },
+       },
+       [3] = {
+               .name = "payload_len",
+               .type = __type_integer(uint16_t, 0, 0, 0, __BIG_ENDIAN, 10, none),
+       },
+       [4] = {
+               .name = "nexthdr",
+               .type = __type_integer(uint8_t, 0, 0, 0, __BIG_ENDIAN, 10, none),
+       },
+       [5] = {
+               .name = "hop_limit",
+               .type = __type_integer(uint8_t, 0, 0, 0, __BIG_ENDIAN, 10, none),
+       },
+       [6] = {
+               .name = "saddr",
+               .type = {
+                       .atype = atype_array,
+                       .u.array.elem_type = __type_integer(uint16_t, 0, 0, 0, __BIG_ENDIAN, 16, none),
+                       .u.array.length = 8,
+                       .u.array.elem_alignment = lttng_alignof(uint16_t),
+               },
+       },
+       [7] = {
+               .name = "daddr",
+               .type = {
+                       .atype = atype_array,
+                       .u.array.elem_type = __type_integer(uint16_t, 0, 0, 0, __BIG_ENDIAN, 16, none),
+                       .u.array.length = 8,
+                       .u.array.elem_alignment = lttng_alignof(uint16_t),
+               },
+       },
+};
+
+static struct lttng_event_field network_fields[] = {
+       [0] = {
+               .name = "unknown",
+               .type = {
+                       .atype = atype_struct,
+                       .u._struct.nr_fields = 0,
+                       .u._struct.fields = emptyfields,
+               },
+       },
+       [1] = {
+               .name = "ipv4",
+               .type = {
+                       .atype = atype_struct,
+                       .u._struct.nr_fields = ARRAY_SIZE(ipv4fields),
+                       .u._struct.fields = ipv4fields,
+               },
+       },
+       [2] = {
+               .name = "ipv6",
+               .type = {
+                       .atype = atype_struct,
+                       .u._struct.nr_fields = ARRAY_SIZE(ipv6fields),
+                       .u._struct.fields = ipv6fields,
+               },
+       },
+};
+
+enum network_header_types {
+       NH_NONE,
+       NH_IPV4,
+       NH_IPV6,
+};
+
+static inline unsigned char __get_network_header_type(struct sk_buff *skb)
+{
+       if (__has_network_hdr(skb)) {
+               if (skb->protocol == htons(ETH_P_IPV6))
+                       return NH_IPV6;
+               else if (skb->protocol == htons(ETH_P_IP))
+                       return NH_IPV4;
+               /* Fallthrough for other header types. */
+       }
+       return NH_NONE;
+}
+
+#endif
+
+LTTNG_TRACEPOINT_ENUM(net_network_header,
+       TP_ENUM_VALUES(
+               ctf_enum_value("_unknown", NH_NONE)
+               ctf_enum_value("_ipv4", NH_IPV4)
+               ctf_enum_value("_ipv6", NH_IPV6)
+       )
+)
 
 LTTNG_TRACEPOINT_EVENT(net_dev_xmit,
 
@@ -49,6 +232,36 @@ LTTNG_TRACEPOINT_EVENT_CLASS(net_dev_template,
                ctf_integer_hex(void *, skbaddr, skb)
                ctf_integer(unsigned int, len, skb->len)
                ctf_string(name, skb->dev->name)
+               ctf_enum(net_network_header, unsigned char,
+                       network_header_type, __get_network_header_type(skb))
+               ctf_custom_field(
+                       ctf_custom_type(
+                               .atype = atype_variant,
+                               .u.variant.tag_name = "network_header_type",
+                               .u.variant.choices = network_fields,
+                               .u.variant.nr_choices = ARRAY_SIZE(network_fields),
+                       ),
+                       network_header,
+                       ctf_custom_code(
+                               switch (__get_network_header_type(skb)) {
+                               case NH_IPV4: {
+                                       ctf_align(uint16_t)
+                                       ctf_array_type(uint8_t, ip_hdr(skb),
+                                                       sizeof(struct iphdr))
+                                       break;
+                               }
+                               case NH_IPV6: {
+                                       ctf_align(uint16_t)
+                                       ctf_array_type(uint8_t, ipv6_hdr(skb),
+                                                       sizeof(struct ipv6hdr))
+                                       break;
+                               }
+                               default:
+                                       /* For any other header type, there is nothing to do. */
+                                       break;
+                               }
+                       )
+               )
        )
 )