feat(errorsx): cover more syscall errors and add tests (#430)

* feat(errorsx): cover more syscall errors and add tests

Part of https://github.com/ooni/probe/issues/1505

* fix tests

internal/errorsx/errno.go

@@ -1,5 +1,5 @@
 // Code generated by go generate; DO NOT EDIT.
-// Generated: 2021-07-02 15:15:17.997258 +0200 CEST m=+0.110031584
+// Generated: 2021-07-02 17:54:06.182341 +0200 CEST m=+0.120124584
 
 package errorsx
 
@@ -10,6 +10,42 @@ import (
 	"syscall"
 )
 
+// This enumeration lists the syscall-derived failures defined at
+// https://github.com/ooni/spec/blob/master/data-formats/df-007-errors.md
+//
+// See also the enumeration at failures.go for the failures that
+// DO NOT derive from system call errors.
+const (
+	FailureOperationCanceled           = "operation_canceled"
+	FailureConnectionRefused           = "connection_refused"
+	FailureConnectionReset             = "connection_reset"
+	FailureHostUnreachable             = "host_unreachable"
+	FailureTimedOut                    = "timed_out"
+	FailureAddressFamilyNotSupported   = "address_family_not_supported"
+	FailureAddressInUse                = "address_in_use"
+	FailureAddressNotAvailable         = "address_not_available"
+	FailureAlreadyConnected            = "already_connected"
+	FailureBadAddress                  = "bad_address"
+	FailureBadFileDescriptor           = "bad_file_descriptor"
+	FailureConnectionAborted           = "connection_aborted"
+	FailureConnectionAlreadyInProgress = "connection_already_in_progress"
+	FailureDestinationAddressRequired  = "destination_address_required"
+	FailureInterrupted                 = "interrupted"
+	FailureInvalidArgument             = "invalid_argument"
+	FailureMessageSize                 = "message_size"
+	FailureNetworkDown                 = "network_down"
+	FailureNetworkReset                = "network_reset"
+	FailureNetworkUnreachable          = "network_unreachable"
+	FailureNoBufferSpace               = "no_buffer_space"
+	FailureNoProtocolOption            = "no_protocol_option"
+	FailureNotASocket                  = "not_a_socket"
+	FailureNotConnected                = "not_connected"
+	FailureOperationWouldBlock         = "operation_would_block"
+	FailurePermissionDenied            = "permission_denied"
+	FailureProtocolNotSupported        = "protocol_not_supported"
+	FailureWrongProtocolType           = "wrong_protocol_type"
+)
+
 // toSyscallErr converts a syscall error to the
 // proper OONI error. Returns the OONI error string
 // on success, an empty string otherwise.
@@ -23,7 +59,7 @@ func toSyscallErr(err error) string {
 	}
 	switch errno {
 	case ECANCELED:
-		return FailureInterrupted
+		return FailureOperationCanceled
 	case ECONNREFUSED:
 		return FailureConnectionRefused
 	case ECONNRESET:
@@ -31,7 +67,53 @@ func toSyscallErr(err error) string {
 	case EHOSTUNREACH:
 		return FailureHostUnreachable
 	case ETIMEDOUT:
-		return FailureGenericTimeoutError
+		return FailureTimedOut
+	case EAFNOSUPPORT:
+		return FailureAddressFamilyNotSupported
+	case EADDRINUSE:
+		return FailureAddressInUse
+	case EADDRNOTAVAIL:
+		return FailureAddressNotAvailable
+	case EISCONN:
+		return FailureAlreadyConnected
+	case EFAULT:
+		return FailureBadAddress
+	case EBADF:
+		return FailureBadFileDescriptor
+	case ECONNABORTED:
+		return FailureConnectionAborted
+	case EALREADY:
+		return FailureConnectionAlreadyInProgress
+	case EDESTADDRREQ:
+		return FailureDestinationAddressRequired
+	case EINTR:
+		return FailureInterrupted
+	case EINVAL:
+		return FailureInvalidArgument
+	case EMSGSIZE:
+		return FailureMessageSize
+	case ENETDOWN:
+		return FailureNetworkDown
+	case ENETRESET:
+		return FailureNetworkReset
+	case ENETUNREACH:
+		return FailureNetworkUnreachable
+	case ENOBUFS:
+		return FailureNoBufferSpace
+	case ENOPROTOOPT:
+		return FailureNoProtocolOption
+	case ENOTSOCK:
+		return FailureNotASocket
+	case ENOTCONN:
+		return FailureNotConnected
+	case EWOULDBLOCK:
+		return FailureOperationWouldBlock
+	case EACCES:
+		return FailurePermissionDenied
+	case EPROTONOSUPPORT:
+		return FailureProtocolNotSupported
+	case EPROTOTYPE:
+		return FailureWrongProtocolType
 	}
 	return ""
 }