func WebSensorsAgent(ctx context.Context, db data.DB, u *models.User) {
// Get the db's changes, then filter by updates, then
// filter by whether this user can read the record
changes := data.Filter(data.FilterKind(db.Changes(), models.EventKind), func(c *data.Change) bool {
ok, _ := access.CanRead(db, u, c.Record)
return ok
})
Run:
for {
select {
case c, ok := <-*changes:
if !ok {
break Run
}
switch c.Record.(*models.Event).Name {
case WEB_SENSOR_LOCATION:
webSensorLocation(db, u, c.Record.(*models.Event).Data)
}
case <-ctx.Done():
break Run
}
}
}
func TaskAgent(ctx context.Context, db data.DB, u *models.User) {
changes := data.Filter(data.FilterKind(db.Changes(), models.EventKind), func(c *data.Change) bool {
ok, _ := access.CanRead(db, u, c.Record)
return ok
})
Run:
for {
select {
case c, ok := <-*changes:
if !ok {
break Run
}
switch c.Record.(*models.Event).Name {
case TaskMakeGoal:
taskMakeGoal(db, u, c.Record.(*models.Event).Data)
case TaskDropGoal:
taskDropGoal(db, u, c.Record.(*models.Event).Data)
}
case <-ctx.Done():
break Run
}
}
}
// execute retrieves the records matching a *query, which the user can read, and marshals them to attr maps.
//
// Errors:
// - db.Query error
// - access.CanRead error
// - iter.Close error
func execute(db data.DB, u *models.User, q *query) ([]map[string]interface{}, error) {
rs := make([]map[string]interface{}, 0)
iter, err := db.Query(q.Kind).Limit(q.Limit).Batch(q.Batch).Skip(q.Skip).Select(q.Select).Order(q.Order...).Execute()
if err != nil {
return nil, err
}
m := models.ModelFor(q.Kind)
for iter.Next(m) {
ok, err := access.CanRead(db, u, m)
if err != nil {
return nil, err
}
if !ok {
continue
}
temp := make(map[string]interface{})
transfer.TransferAttrs(m, &temp)
rs = append(rs, temp)
m = models.ModelFor(q.Kind)
}
if err := iter.Close(); err != nil {
return nil, err
}
return rs, nil
}
func LocationAgent(ctx context.Context, db data.DB, u *models.User) {
locTag, err := tag.ForName(db, u, tag.Location)
if err != nil {
log.Fatal(err)
}
updTag, err := tag.ForName(db, u, tag.Update)
if err != nil {
log.Fatal(err)
}
// Get the db's changes, then filter by updates, then
// filter by whether this user can read the record
changes := data.Filter(data.FilterKind(db.Changes(), models.EventKind), func(c *data.Change) bool {
ok, _ := access.CanRead(db, u, c.Record)
if !ok {
return false
}
return event.ContainsTags(c.Record.(*models.Event), locTag, updTag)
})
Run:
for {
select {
case c, ok := <-*changes:
if !ok {
break Run
}
locationUpdate(db, u, c.Record.(*models.Event))
case <-ctx.Done():
break Run
}
}
}
func RecordChangesGET(ctx context.Context, ws *websocket.Conn, db data.DB, logger services.Logger) {
l := logger.WithPrefix("RecordChangesGet: ")
u, ok := user.FromContext(ctx)
if !ok {
l.Print("failed to retrieve user from context")
return
}
// Get the db's changes, then filter by updates, then
// filter by whether this user can read the record
changes := data.Filter(db.Changes(), func(c *data.Change) bool {
ok, err := access.CanRead(db, u, c.Record)
if err != nil {
l.Printf("error checking access control: %s", err)
}
return ok
})
var kind data.Kind
if kindParam := ws.Request().Form.Get(kindParam); kindParam != "" {
kind = data.Kind(kindParam)
if _, ok := models.Kinds[kind]; !ok {
l.Printf("unrecognized kind: %q", kind)
if err := websocket.Message.Send(ws, fmt.Sprintf("The kind %q is not recognized", kind)); err != nil {
if err != io.EOF {
l.Printf("error sending on websocket: %s", err)
}
}
return
}
// If a kind was specified, filter by it
changes = data.FilterKind(changes, kind)
}
for {
select {
case change, ok := <-*changes:
if !ok {
l.Printf("change channel was closed")
return
}
l.Printf("recieved change: %+v", change)
changeTransport := transfer.Change(change)
if err := websocket.JSON.Send(ws, changeTransport); err != nil {
if err != io.EOF {
l.Printf("error sending to socket: %s", err)
}
return
}
case <-time.After(5 * time.Second):
l.Printf("no change in 5 seconds, but still listening")
case <-ctx.Done():
l.Printf("context cancelled")
// context was cancelled
return
}
}
}
// RecordQueryPOST implements gaia's response to a POST request to the '/record/query/' endpoint.
//
// Assumptions: The user has been authenticated.
//
// Proceedings:
//
// Success:
// * StatusOK
//
// Error:
// * InternalServerError: parsing url params,
// * BadRequest: no kind parameter, unrecognized kind
func RecordQueryPOST(ctx context.Context, w http.ResponseWriter, r *http.Request, logger services.Logger, db data.DB) {
l := logger.WithPrefix("RecordQueryPOST: ")
// Parse the form
if err := r.ParseForm(); err != nil {
l.Printf("error parsing form: %s", err)
http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
return
}
// Retrieve the kind parameter
k := r.FormValue(kindParam)
if k == "" {
l.Printf("no kind parameter")
http.Error(w, fmt.Sprintf("You must specify a %q parameter", kindParam), http.StatusBadRequest)
return
}
kind := data.Kind(k)
// Verify the kind is recognized
if !models.Kinds[kind] {
l.Printf("unrecognized kind %q", kind)
http.Error(w, fmt.Sprintf("The kind %q is not recognized", kind), http.StatusBadRequest)
return
}
// Retrieve the limit, batch and skip parameters
lim := r.FormValue(limitParam)
bat := r.FormValue(batchParam)
ski := r.FormValue(skipParam)
// Set up the variables to apply to the query
var limit, batch, skip int
if lim != "" {
limit, _ = strconv.Atoi(lim)
} else if bat != "" {
batch, _ = strconv.Atoi(bat)
} else if ski != "" {
skip, _ = strconv.Atoi(ski)
}
// Read the selection attrs from the body
var requestBody []byte
var err error
defer r.Body.Close()
if requestBody, err = ioutil.ReadAll(r.Body); err != nil {
l.Printf("error while reading request body: %s", err)
http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
return
}
// These are the selectors, unmarshal the request body into them
attrs := make(data.AttrMap)
// only unmarshall if there is any request body
if len(requestBody) > 0 {
if err = json.Unmarshal(requestBody, &attrs); err != nil {
l.Printf("info: request body:\n%s", string(requestBody))
l.Printf("error: while unmarshalling request body, %s", err)
http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
return
}
}
// Retrieve the user we are acting on behalf
u, ok := user.FromContext(ctx)
if !ok {
l.Print("failed to retrieve user from context")
http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
return
}
// Load our actual query
var iter data.Iterator
if iter, err = db.Query(kind).Select(attrs).Limit(limit).Batch(batch).Skip(skip).Order(r.Form["order"]...).Execute(); err != nil {
l.Printf("db.Query(%q).Select(%v).Limit(%d).Batch(%d).Skip(%d) error: %s", kind, attrs, limit, batch, skip, err)
http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
return
}
fmt.Fprint(w, "[")
first := true
// Iterator through the results and write the response
m := models.ModelFor(kind)
for iter.Next(m) {
if !first {
fmt.Fprint(w, ",")
}
first = false
if ok, err := access.CanRead(db, u, m); err != nil {
// We've hit an error and need to bail
l.Printf("access.CanRead error: %s", err)
http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
return
} else if ok {
bytes, err := json.Marshal(m)
if err != nil {
l.Printf("error marshalling JSON: %s", err)
http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
return
}
w.Write(bytes)
}
}
if err := iter.Close(); err != nil {
l.Printf("error closing query, %s", err)
http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
return
}
fmt.Fprint(w, "]")
}
// RecordGET implements gaia's response to a GET request to the '/record/' endpoint.
//
// Assumptions: The user has been authenticated.
//
// Proceedings: Parses the url parameters, retrieving the kind and id parameters (both required).
// Then it loads that record, checks if the user is allowed to access it, if so it returns the model as JSON.
//
// Success:
// * StatusOK with the record as JSON
//
// Errors:
// * InternalServerError: failure to parse the parameters, database connections, json marshalling
// * BadRequest: no kind param, no id param, unrecognized kind, invalid id
// * NotFound: unauthorized, record actually doesn't exist
func RecordGET(ctx context.Context, w http.ResponseWriter, r *http.Request, logger services.Logger, db services.DB) {
l := logger.WithPrefix("RecordGet: ")
// Parse the form value
if err := r.ParseForm(); err != nil {
l.Printf("error parsing form: %s", err)
http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
return
}
// Secure the kind parameter's existence, and superficial validity (i.e., non-empty)
k := r.FormValue(kindParam)
if k == "" {
l.Printf("no kind parameter")
http.Error(w, fmt.Sprintf("You must specify a '%s' parameter", kindParam), http.StatusBadRequest)
return
}
kind := data.Kind(k)
// Secure the id parameter's existence, and superficial validity (i.e., non-empty)
i := r.FormValue(idParam)
if i == "" {
l.Printf("no id parameter")
http.Error(w, fmt.Sprintf("You must specify a '%s' parameter", idParam), http.StatusBadRequest)
return
}
// Ensure the kind is recognized
if _, ok := models.Kinds[kind]; !ok {
l.Printf("unrecognized kind: %q", kind)
http.Error(w, fmt.Sprintf("The kind %q is not recognized", kind), http.StatusBadRequest)
return
}
// Ensure the id is valid
id, err := db.ParseID(i)
if err != nil {
l.Printf("unrecognized id: %q, err: %s", i, err)
http.Error(w, fmt.Sprintf("The id %q is invalid", i), http.StatusBadRequest)
return
}
m := models.ModelFor(kind)
m.SetID(id)
if err := db.PopulateByID(m); err != nil {
switch err {
// ErrAccessDenial and ErrNotFound are "normal" courses, in the sense that they
// may be expected in normal usage.
case data.ErrAccessDenial:
fallthrough // don't leak information, make it look like a 404
case data.ErrNotFound:
// This is, by far, the most common error case here.
http.Error(w, http.StatusText(http.StatusNotFound), http.StatusNotFound)
// ErrNoConnection, ErrInvalidID and the under-determined errors are all non-normal cases
case data.ErrNoConnection:
fallthrough
case data.ErrInvalidID:
fallthrough
default:
http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
}
l.Printf("db.PopulateByID error: %s", err)
return // regardless of what the error was, we are bailing
}
// Retrieve the user this request was authenticated as
u, ok := user.FromContext(ctx)
if !ok { // This is certainly an issue, and should _never_ happen
l.Print("failed to retrieve user from context")
http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
return
}
// Now we impose the system access control, beyond the database access control
// TODO: limit the domain of errors CanRead returns
if allowed, err := access.CanRead(db, u, m); err != nil {
switch err {
// Again, though odd, both of these are arguably expected
case data.ErrAccessDenial:
fallthrough // don't leak information
case data.ErrNotFound:
http.Error(w, http.StatusText(http.StatusNotFound), http.StatusNotFound)
// These are not-expected
case data.ErrNoConnection:
fallthrough
case data.ErrInvalidID:
fallthrough
default:
http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
}
l.Printf("access.CanRead error: %s", err)
return
} else if !allowed {
// If you can't read the record you are asking for,
// it "does not exist" as far as you are concerned
l.Print("access denied")
http.Error(w, http.StatusText(http.StatusNotFound), http.StatusNotFound)
return
}
bytes, err := json.MarshalIndent(m, "", " ")
if err != nil {
l.Printf("error while marshalling json %s", err)
http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
return
}
w.WriteHeader(http.StatusOK)
w.Header().Set("Content-Type", "application/json")
w.Write(bytes)
}