Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Fix gRPC server instrumentation detection of incoming headers #558

Merged
merged 1 commit into from
Dec 13, 2023
Merged

Fix gRPC server instrumentation detection of incoming headers #558

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 1 addition & 1 deletion internal/pkg/instrumentation/bpf/google.golang.org/grpc/server/bpf/probe.bpf.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -67,6 +67,7 @@ volatile const u64 frame_fields_pos;
volatile const u64 frame_stream_id_pod;
volatile const u64 stream_id_pos;
volatile const u64 stream_ctx_pos;
volatile const u64 frame_pos;

// This instrumentation attaches uprobe to the following function:
// func (s *Server) handleStream(t transport.ServerTransport, stream *transport.Stream, trInfo *traceInfo)
Expand Down Expand Up @@ -126,7 +127,6 @@ UPROBE_RETURN(server_handleStream, struct grpc_request_t, grpc_events, events, 4
SEC("uprobe/http2Server_operateHeader")
int uprobe_http2Server_operateHeader(struct pt_regs *ctx)
{
u64 frame_pos = 2;
void *frame_ptr = get_argument(ctx, frame_pos);
struct go_slice header_fields = {};
bpf_probe_read(&header_fields, sizeof(header_fields), (void *)(frame_ptr + frame_fields_pos));
Expand Down
27 changes: 27 additions & 0 deletions internal/pkg/instrumentation/bpf/google.golang.org/grpc/server/probe.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -15,16 +15,19 @@
package server

import (
"fmt"
"os"

"github.com/cilium/ebpf/link"
"github.com/cilium/ebpf/perf"
"github.com/go-logr/logr"
"github.com/hashicorp/go-version"
"go.opentelemetry.io/otel/attribute"
semconv "go.opentelemetry.io/otel/semconv/v1.21.0"
"go.opentelemetry.io/otel/trace"
"golang.org/x/sys/unix"

"go.opentelemetry.io/auto/internal/pkg/inject"
"go.opentelemetry.io/auto/internal/pkg/instrumentation/context"
"go.opentelemetry.io/auto/internal/pkg/instrumentation/probe"
"go.opentelemetry.io/auto/internal/pkg/process"
Expand Down Expand Up @@ -69,6 +72,7 @@ func New(logger logr.Logger) probe.Probe {
Key: "frame_stream_id_pod",
Val: structfield.NewID("golang.org/x/net", "golang.org/x/net/http2", "FrameHeader", "StreamID"),
},
framePosConst{},
},
Uprobes: []probe.Uprobe[bpfObjects]{
{
Expand All @@ -89,6 +93,29 @@ func New(logger logr.Logger) probe.Probe {
}
}

// framePosConst is a Probe Const defining the position of the
// http.MetaHeadersFrame parameter of the http2Server.operateHeaders method.
type framePosConst struct{}

// Prior to v1.60.0 the frame parameter was first. However, in that version a
// context was added as the first parameter. The frame became the second
// parameter:
// https://github.com/grpc/grpc-go/pull/6716/files#diff-4058722211b8d52e2d5b0c0b7542059ed447a04017b69520d767e94a9493409eR334
var paramChangeVer = version.Must(version.NewVersion("1.60.0"))

func (c framePosConst) InjectOption(td *process.TargetDetails) (inject.Option, error) {
ver, ok := td.Libraries[pkg]
if !ok {
return nil, fmt.Errorf("unknown module version: %s", pkg)
}

var pos uint64 = 2
if ver.GreaterThanOrEqual(paramChangeVer) {
pos = 4
}
return inject.WithKeyValue("frame_pos", pos), nil
}

func uprobeHandleStream(name string, exec *link.Executable, target *process.TargetDetails, obj *bpfObjects) ([]link.Link, error) {
offset, err := target.GetFunctionOffset(name)
if err != nil {
Expand Down
Loading