github.com/kubiko/snapd@v0.0.0-20201013125620-d4f3094d9ddf/interfaces/kmod/spec.go (about)

     1  // -*- Mode: Go; indent-tabs-mode: t -*-
     2  
     3  /*
     4   * Copyright (C) 2017 Canonical Ltd
     5   *
     6   * This program is free software: you can redistribute it and/or modify
     7   * it under the terms of the GNU General Public License version 3 as
     8   * published by the Free Software Foundation.
     9   *
    10   * This program is distributed in the hope that it will be useful,
    11   * but WITHOUT ANY WARRANTY; without even the implied warranty of
    12   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    13   * GNU General Public License for more details.
    14   *
    15   * You should have received a copy of the GNU General Public License
    16   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
    17   *
    18   */
    19  
    20  package kmod
    21  
    22  import (
    23  	"strings"
    24  
    25  	"github.com/snapcore/snapd/interfaces"
    26  	"github.com/snapcore/snapd/snap"
    27  )
    28  
    29  // Specification assists in collecting kernel modules associated with an interface.
    30  //
    31  // Unlike the Backend itself (which is stateless and non-persistent) this type
    32  // holds internal state that is used by the kmod backend during the interface
    33  // setup process.
    34  type Specification struct {
    35  	modules map[string]bool
    36  }
    37  
    38  // AddModule adds a kernel module, trimming spaces and ignoring duplicated modules.
    39  func (spec *Specification) AddModule(module string) error {
    40  	m := strings.TrimSpace(module)
    41  	if m == "" {
    42  		return nil
    43  	}
    44  	if spec.modules == nil {
    45  		spec.modules = make(map[string]bool)
    46  	}
    47  	spec.modules[m] = true
    48  	return nil
    49  }
    50  
    51  // Modules returns a copy of the kernel module names added.
    52  func (spec *Specification) Modules() map[string]bool {
    53  	result := make(map[string]bool, len(spec.modules))
    54  	for k, v := range spec.modules {
    55  		result[k] = v
    56  	}
    57  	return result
    58  }
    59  
    60  // Implementation of methods required by interfaces.Specification
    61  
    62  // AddConnectedPlug records kmod-specific side-effects of having a connected plug.
    63  func (spec *Specification) AddConnectedPlug(iface interfaces.Interface, plug *interfaces.ConnectedPlug, slot *interfaces.ConnectedSlot) error {
    64  	type definer interface {
    65  		KModConnectedPlug(spec *Specification, plug *interfaces.ConnectedPlug, slot *interfaces.ConnectedSlot) error
    66  	}
    67  	if iface, ok := iface.(definer); ok {
    68  		return iface.KModConnectedPlug(spec, plug, slot)
    69  	}
    70  	return nil
    71  }
    72  
    73  // AddConnectedSlot records mount-specific side-effects of having a connected slot.
    74  func (spec *Specification) AddConnectedSlot(iface interfaces.Interface, plug *interfaces.ConnectedPlug, slot *interfaces.ConnectedSlot) error {
    75  	type definer interface {
    76  		KModConnectedSlot(spec *Specification, plug *interfaces.ConnectedPlug, slot *interfaces.ConnectedSlot) error
    77  	}
    78  	if iface, ok := iface.(definer); ok {
    79  		return iface.KModConnectedSlot(spec, plug, slot)
    80  	}
    81  	return nil
    82  }
    83  
    84  // AddPermanentPlug records mount-specific side-effects of having a plug.
    85  func (spec *Specification) AddPermanentPlug(iface interfaces.Interface, plug *snap.PlugInfo) error {
    86  	type definer interface {
    87  		KModPermanentPlug(spec *Specification, plug *snap.PlugInfo) error
    88  	}
    89  	if iface, ok := iface.(definer); ok {
    90  		return iface.KModPermanentPlug(spec, plug)
    91  	}
    92  	return nil
    93  }
    94  
    95  // AddPermanentSlot records mount-specific side-effects of having a slot.
    96  func (spec *Specification) AddPermanentSlot(iface interfaces.Interface, slot *snap.SlotInfo) error {
    97  	type definer interface {
    98  		KModPermanentSlot(spec *Specification, slot *snap.SlotInfo) error
    99  	}
   100  	if iface, ok := iface.(definer); ok {
   101  		return iface.KModPermanentSlot(spec, slot)
   102  	}
   103  	return nil
   104  }