super-graph/serv/core.go

389 lines
7.0 KiB
Go

package serv
import (
"bytes"
"context"
"encoding/json"
"errors"
"fmt"
"io"
"net/http"
"time"
"github.com/cespare/xxhash/v2"
"github.com/dosco/super-graph/qcode"
"github.com/jackc/pgx/v4"
"github.com/valyala/fasttemplate"
)
type coreContext struct {
req gqlReq
res gqlResp
context.Context
}
func (c *coreContext) handleReq(w io.Writer, req *http.Request) error {
c.req.ref = req.Referer()
c.req.hdr = req.Header
if len(c.req.Vars) == 2 {
c.req.Vars = nil
}
if authCheck(c) {
c.req.role = "user"
} else {
c.req.role = "anon"
}
b, err := c.execQuery()
if err != nil {
return err
}
return c.render(w, b)
}
func (c *coreContext) execQuery() ([]byte, error) {
var data []byte
var st *stmt
var err error
if conf.Production {
data, st, err = c.resolvePreparedSQL()
if err != nil {
logger.Error().
Err(err).
Str("default_role", c.req.role).
Msg(c.req.Query)
return nil, errors.New("query failed. check logs for error")
}
} else {
if data, st, err = c.resolveSQL(); err != nil {
return nil, err
}
}
return execRemoteJoin(st, data, c.req.hdr)
}
func (c *coreContext) resolvePreparedSQL() ([]byte, *stmt, error) {
var tx pgx.Tx
var err error
qt := qcode.GetQType(c.req.Query)
mutation := (qt == qcode.QTMutation)
useRoleQuery := conf.isABACEnabled() && mutation
useTx := useRoleQuery || conf.DB.SetUserID
if useTx {
if tx, err = db.Begin(c.Context); err != nil {
return nil, nil, err
}
defer tx.Rollback(c) //nolint: errcheck
}
if conf.DB.SetUserID {
if err := setLocalUserID(c.Context, tx); err != nil {
return nil, nil, err
}
}
var role string
if useRoleQuery {
if role, err = c.executeRoleQuery(tx); err != nil {
return nil, nil, err
}
} else if v := c.Value(userRoleKey); v != nil {
role = v.(string)
} else {
role = c.req.role
}
ps, ok := _preparedList[gqlHash(c.req.Query, c.req.Vars, role)]
if !ok {
return nil, nil, errUnauthorized
}
var root []byte
var row pgx.Row
vars, err := argList(c, ps.args)
if err != nil {
return nil, nil, err
}
if useTx {
row = tx.QueryRow(c.Context, ps.sd.SQL, vars...)
} else {
row = db.QueryRow(c.Context, ps.sd.SQL, vars...)
}
if ps.roleArg {
err = row.Scan(&role, &root)
} else {
err = row.Scan(&root)
}
if len(role) == 0 {
logger.Debug().Str("default_role", c.req.role).Msg(c.req.Query)
} else {
logger.Debug().Str("default_role", c.req.role).Str("role", role).Msg(c.req.Query)
}
if err != nil {
return nil, nil, err
}
c.req.role = role
if useTx {
if err := tx.Commit(c.Context); err != nil {
return nil, nil, err
}
}
return root, &ps.st, nil
}
func (c *coreContext) resolveSQL() ([]byte, *stmt, error) {
var tx pgx.Tx
var err error
qt := qcode.GetQType(c.req.Query)
mutation := (qt == qcode.QTMutation)
useRoleQuery := conf.isABACEnabled() && mutation
useTx := useRoleQuery || conf.DB.SetUserID
if useTx {
if tx, err = db.Begin(c.Context); err != nil {
return nil, nil, err
}
defer tx.Rollback(c.Context) //nolint: errcheck
}
if conf.DB.SetUserID {
if err := setLocalUserID(c.Context, tx); err != nil {
return nil, nil, err
}
}
if useRoleQuery {
if c.req.role, err = c.executeRoleQuery(tx); err != nil {
return nil, nil, err
}
} else if v := c.Value(userRoleKey); v != nil {
c.req.role = v.(string)
}
stmts, err := buildStmt(qt, []byte(c.req.Query), c.req.Vars, c.req.role)
if err != nil {
return nil, nil, err
}
st := &stmts[0]
t := fasttemplate.New(st.sql, openVar, closeVar)
buf := &bytes.Buffer{}
_, err = t.ExecuteFunc(buf, argMap(c, c.req.Vars))
if err != nil {
return nil, nil, err
}
finalSQL := buf.String()
var stime time.Time
if conf.EnableTracing {
stime = time.Now()
}
var root []byte
var role string
var row pgx.Row
defaultRole := c.req.role
if useTx {
row = tx.QueryRow(c.Context, finalSQL)
} else {
row = db.QueryRow(c.Context, finalSQL)
}
if len(stmts) > 1 {
err = row.Scan(&role, &root)
} else {
err = row.Scan(&root)
}
if len(role) == 0 {
logger.Debug().Str("default_role", defaultRole).Msg(c.req.Query)
} else {
logger.Debug().Str("default_role", defaultRole).Str("role", role).Msg(c.req.Query)
}
if err != nil {
return nil, nil, err
}
if useTx {
if err := tx.Commit(c.Context); err != nil {
return nil, nil, err
}
}
if !conf.Production {
_allowList.add(&c.req)
}
if len(stmts) > 1 {
if st = findStmt(role, stmts); st == nil {
return nil, nil, fmt.Errorf("invalid role '%s' returned", role)
}
}
if conf.EnableTracing {
for _, id := range st.qc.Roots {
c.addTrace(st.qc.Selects, id, stime)
}
}
return root, st, nil
}
func (c *coreContext) executeRoleQuery(tx pgx.Tx) (string, error) {
var role string
row := tx.QueryRow(c.Context, "_sg_get_role", c.req.role, 1)
if err := row.Scan(&role); err != nil {
return "", err
}
return role, nil
}
func (c *coreContext) render(w io.Writer, data []byte) error {
c.res.Data = json.RawMessage(data)
return json.NewEncoder(w).Encode(c.res)
}
func (c *coreContext) addTrace(sel []qcode.Select, id int32, st time.Time) {
et := time.Now()
du := et.Sub(st)
if c.res.Extensions == nil {
c.res.Extensions = &extensions{&trace{
Version: 1,
StartTime: st,
Execution: execution{},
}}
}
c.res.Extensions.Tracing.EndTime = et
c.res.Extensions.Tracing.Duration = du
n := 1
for i := id; i != -1; i = sel[i].ParentID {
n++
}
path := make([]string, n)
n--
for i := id; ; i = sel[i].ParentID {
path[n] = sel[i].Name
if sel[i].ParentID == -1 {
break
}
n--
}
tr := resolver{
Path: path,
ParentType: "Query",
FieldName: sel[id].Name,
ReturnType: "object",
StartOffset: 1,
Duration: du,
}
c.res.Extensions.Tracing.Execution.Resolvers =
append(c.res.Extensions.Tracing.Execution.Resolvers, tr)
}
func setLocalUserID(c context.Context, tx pgx.Tx) error {
var err error
if v := c.Value(userIDKey); v != nil {
_, err = tx.Exec(context.Background(), fmt.Sprintf(`SET LOCAL "user.id" = %s;`, v))
}
return err
}
func parentFieldIds(h *xxhash.Digest, sel []qcode.Select, skipped uint32) (
[][]byte,
map[uint64]*qcode.Select) {
c := 0
for i := range sel {
s := &sel[i]
if isSkipped(skipped, uint32(s.ID)) {
c++
}
}
// list of keys (and it's related value) to extract from
// the db json response
fm := make([][]byte, c)
// mapping between the above extracted key and a Select
// object
sm := make(map[uint64]*qcode.Select, c)
n := 0
for i := range sel {
s := &sel[i]
if !isSkipped(skipped, uint32(s.ID)) {
continue
}
p := sel[s.ParentID]
k := mkkey(h, s.Name, p.Name)
if r, ok := rmap[k]; ok {
fm[n] = r.IDField
n++
k := xxhash.Sum64(r.IDField)
sm[k] = s
}
}
return fm, sm
}
func isSkipped(n uint32, pos uint32) bool {
return ((n & (1 << pos)) != 0)
}
func authCheck(ctx *coreContext) bool {
return (ctx.Value(userIDKey) != nil)
}
func colsToList(cols []qcode.Column) []string {
var f []string
for i := range cols {
f = append(f, cols[i].Name)
}
return f
}