syz-cluster: add email-reporter component

Add the high-level logic for the email-reporter component that will
be responsible for sending bug reports and reacting to incoming emails.

1 files changed, 143 insertions, 0 deletions

diff --git a/syz-cluster/email-reporter/handler.go b/syz-cluster/email-reporter/handler.go
new file mode 100644
index 000000000..a956b77f9
--- /dev/null
+++ b/syz-cluster/email-reporter/handler.go
@@ -0,0 +1,143 @@
+// Copyright 2025 syzkaller project authors. All rights reserved.
+// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+
+package main
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"time"
+
+	"github.com/google/syzkaller/pkg/email"
+	"github.com/google/syzkaller/syz-cluster/pkg/api"
+	"github.com/google/syzkaller/syz-cluster/pkg/app"
+	"github.com/google/syzkaller/syz-cluster/pkg/report"
+)
+
+type EmailToSend struct {
+	To        []string
+	Cc        []string
+	Subject   string
+	InReplyTo string
+	Body      []byte
+}
+
+type SendEmailCb func(context.Context, *EmailToSend) (string, error)
+
+type Handler struct {
+	apiClient   *api.ReporterClient
+	emailConfig *app.EmailConfig
+	sender      SendEmailCb
+}
+
+func (h *Handler) PollReportsLoop(ctx context.Context, pollPeriod time.Duration) {
+	for {
+		_, err := h.PollAndReport(ctx)
+		if err != nil {
+			app.Errorf("%v", err)
+		}
+		select {
+		case <-ctx.Done():
+			return
+		case <-time.After(pollPeriod):
+		}
+	}
+}
+
+func (h *Handler) PollAndReport(ctx context.Context) (*api.SessionReport, error) {
+	reply, err := h.apiClient.GetNextReport(ctx, api.EmailReporter)
+	if err != nil {
+		return nil, fmt.Errorf("failed to poll the next report: %w", err)
+	} else if reply == nil || reply.Report == nil {
+		return nil, nil
+	}
+	report := reply.Report
+	log.Printf("report %q is to be sent", report.ID)
+	if err := h.report(ctx, report); err != nil {
+		// TODO: consider retrying if the error happened before we attempted
+		// to actually send the message.
+		return nil, fmt.Errorf("failed to report %q: %w", report.ID, err)
+	}
+	return report, nil
+}
+
+func (h *Handler) report(ctx context.Context, rep *api.SessionReport) error {
+	// Start by confirming the report - it's better to not send an email at all than to send it multiple times.
+	err := h.apiClient.ConfirmReport(ctx, rep.ID)
+	if err != nil {
+		return fmt.Errorf("failed to confirm: %w", err)
+	}
+
+	// Construct and send the message.
+	body, err := report.Render(rep, h.emailConfig)
+	if err != nil {
+		// This should never be happening..
+		return fmt.Errorf("failed to render the template: %w", err)
+	}
+	toSend := &EmailToSend{
+		Subject: "Re: " + rep.Series.Title, // TODO: use the original rather than the stripped title.
+		To:      rep.Cc,
+		Body:    body,
+	}
+	if rep.Moderation {
+		toSend.To = []string{h.emailConfig.ModerationList}
+	} else {
+		// We assume that email reporting is used for series received over emails.
+		toSend.InReplyTo = rep.Series.ExtID
+		toSend.To = rep.Cc
+		toSend.Cc = []string{h.emailConfig.ArchiveList}
+	}
+	msgID, err := h.sender(ctx, toSend)
+	if err != nil {
+		return fmt.Errorf("failed to send: %w", err)
+	}
+
+	// Now that the report is sent, update the link to the email discussion.
+	err = h.apiClient.UpdateReport(ctx, rep.ID, &api.UpdateReportReq{
+		// TODO: for Lore emails, set Link = lore.Link(msgID).
+		MessageID: msgID,
+	})
+	if err != nil {
+		return fmt.Errorf("failed to update: %w", err)
+	}
+	return nil
+}
+
+// IncomingEmail assumes that the related report ID is already extracted and resides in msg.BugIDs.
+func (h *Handler) IncomingEmail(ctx context.Context, msg *email.Email) error {
+	if len(msg.BugIDs) == 0 {
+		// Unrelated email.
+		return nil
+	}
+	reportID := msg.BugIDs[0]
+
+	var reply string
+	for _, command := range msg.Commands {
+		switch command.Command {
+		case email.CmdUpstream:
+			err := h.apiClient.UpstreamReport(ctx, reportID, &api.UpstreamReportReq{
+				User: msg.Author,
+			})
+			if err != nil {
+				reply = fmt.Sprintf("Failed to process the command. Contact %s.",
+					h.emailConfig.SupportEmail)
+			}
+			// Reply nothing on success.
+		default:
+			reply = "Unknown command"
+		}
+	}
+
+	if reply == "" {
+		return nil
+	}
+	_, err := h.sender(ctx, &EmailToSend{
+		To:        []string{msg.Author},
+		Cc:        msg.Cc,
+		Subject:   "Re: " + msg.Subject,
+		InReplyTo: msg.MessageID,
+		Body:      []byte(email.FormReply(msg, reply)),
+	})
+	return err
+}