1/**
2 * @file
3 * SNMP scalar node support implementation.
4 */
5
6/*
7 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
8 * All rights reserved.
9 *
10 * Redistribution and use in source and binary forms, with or without modification,
11 * are permitted provided that the following conditions are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright notice,
14 *    this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright notice,
16 *    this list of conditions and the following disclaimer in the documentation
17 *    and/or other materials provided with the distribution.
18 * 3. The name of the author may not be used to endorse or promote products
19 *    derived from this software without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
22 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
23 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
24 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
25 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
26 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
29 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
30 * OF SUCH DAMAGE.
31 *
32 * This file is part of the lwIP TCP/IP stack.
33 *
34 * Author: Martin Hentschel <info@cl-soft.de>
35 *
36 */
37
38#include "lwip/apps/snmp_opts.h"
39
40#if LWIP_SNMP /* don't build if not configured for use in lwipopts.h */
41
42#include "lwip/apps/snmp_scalar.h"
43#include "lwip/apps/snmp_core.h"
44
45static s16_t snmp_scalar_array_get_value(struct snmp_node_instance* instance, void* value);
46static snmp_err_t  snmp_scalar_array_set_test(struct snmp_node_instance* instance, u16_t value_len, void* value);
47static snmp_err_t  snmp_scalar_array_set_value(struct snmp_node_instance* instance, u16_t value_len, void* value);
48
49snmp_err_t
50snmp_scalar_get_instance(const u32_t *root_oid, u8_t root_oid_len, struct snmp_node_instance* instance)
51{
52  const struct snmp_scalar_node* scalar_node = (const struct snmp_scalar_node*)(const void*)instance->node;
53
54  LWIP_UNUSED_ARG(root_oid);
55  LWIP_UNUSED_ARG(root_oid_len);
56
57  /* scalar only has one dedicated instance: .0 */
58  if ((instance->instance_oid.len != 1) || (instance->instance_oid.id[0] != 0)) {
59    return SNMP_ERR_NOSUCHINSTANCE;
60  }
61
62  instance->access    = scalar_node->access;
63  instance->asn1_type = scalar_node->asn1_type;
64  instance->get_value = scalar_node->get_value;
65  instance->set_test  = scalar_node->set_test;
66  instance->set_value = scalar_node->set_value;
67  return SNMP_ERR_NOERROR;
68}
69
70snmp_err_t
71snmp_scalar_get_next_instance(const u32_t *root_oid, u8_t root_oid_len, struct snmp_node_instance* instance)
72{
73  /* because our only instance is .0 we can only return a next instance if no instance oid is passed */
74  if (instance->instance_oid.len == 0) {
75    instance->instance_oid.len   = 1;
76    instance->instance_oid.id[0] = 0;
77
78    return snmp_scalar_get_instance(root_oid, root_oid_len, instance);
79  }
80
81  return SNMP_ERR_NOSUCHINSTANCE;
82}
83
84
85snmp_err_t
86snmp_scalar_array_get_instance(const u32_t *root_oid, u8_t root_oid_len, struct snmp_node_instance* instance)
87{
88  LWIP_UNUSED_ARG(root_oid);
89  LWIP_UNUSED_ARG(root_oid_len);
90
91  if ((instance->instance_oid.len == 2) && (instance->instance_oid.id[1] == 0)) {
92    const struct snmp_scalar_array_node* array_node = (const struct snmp_scalar_array_node*)(const void*)instance->node;
93    const struct snmp_scalar_array_node_def* array_node_def = array_node->array_nodes;
94    u32_t i = 0;
95
96    while (i < array_node->array_node_count) {
97      if (array_node_def->oid == instance->instance_oid.id[0]) {
98        break;
99      }
100
101      array_node_def++;
102      i++;
103    }
104
105    if (i < array_node->array_node_count) {
106      instance->access              = array_node_def->access;
107      instance->asn1_type           = array_node_def->asn1_type;
108      instance->get_value           = snmp_scalar_array_get_value;
109      instance->set_test            = snmp_scalar_array_set_test;
110      instance->set_value           = snmp_scalar_array_set_value;
111      instance->reference.const_ptr = array_node_def;
112
113      return SNMP_ERR_NOERROR;
114    }
115  }
116
117  return SNMP_ERR_NOSUCHINSTANCE;
118}
119
120snmp_err_t
121snmp_scalar_array_get_next_instance(const u32_t *root_oid, u8_t root_oid_len, struct snmp_node_instance* instance)
122{
123  const struct snmp_scalar_array_node* array_node = (const struct snmp_scalar_array_node*)(const void*)instance->node;
124  const struct snmp_scalar_array_node_def* array_node_def = array_node->array_nodes;
125  const struct snmp_scalar_array_node_def* result = NULL;
126
127  LWIP_UNUSED_ARG(root_oid);
128  LWIP_UNUSED_ARG(root_oid_len);
129
130  if ((instance->instance_oid.len == 0) && (array_node->array_node_count > 0)) {
131    /* return node with lowest OID */
132    u16_t i = 0;
133
134    result = array_node_def;
135    array_node_def++;
136
137    for (i = 1; i < array_node->array_node_count; i++) {
138      if (array_node_def->oid < result->oid) {
139        result = array_node_def;
140      }
141      array_node_def++;
142    }
143  } else if (instance->instance_oid.len >= 1) {
144    if (instance->instance_oid.len == 1) {
145      /* if we have the requested OID we return its instance, otherwise we search for the next available */
146      u16_t i = 0;
147      while (i < array_node->array_node_count) {
148        if (array_node_def->oid == instance->instance_oid.id[0]) {
149          result = array_node_def;
150          break;
151        }
152
153        array_node_def++;
154        i++;
155      }
156    }
157    if (result == NULL) {
158      u32_t oid_dist = 0xFFFFFFFFUL;
159      u16_t i        = 0;
160      array_node_def = array_node->array_nodes; /* may be already at the end when if case before was executed without result -> reinitialize to start */
161      while (i < array_node->array_node_count) {
162        if ((array_node_def->oid > instance->instance_oid.id[0]) &&
163            ((u32_t)(array_node_def->oid - instance->instance_oid.id[0]) < oid_dist)) {
164          result   = array_node_def;
165          oid_dist = array_node_def->oid - instance->instance_oid.id[0];
166        }
167
168        array_node_def++;
169        i++;
170      }
171    }
172  }
173
174  if (result == NULL) {
175    /* nothing to return */
176    return SNMP_ERR_NOSUCHINSTANCE;
177  }
178
179  instance->instance_oid.len   = 2;
180  instance->instance_oid.id[0] = result->oid;
181  instance->instance_oid.id[1] = 0;
182
183  instance->access              = result->access;
184  instance->asn1_type           = result->asn1_type;
185  instance->get_value           = snmp_scalar_array_get_value;
186  instance->set_test            = snmp_scalar_array_set_test;
187  instance->set_value           = snmp_scalar_array_set_value;
188  instance->reference.const_ptr = result;
189
190  return SNMP_ERR_NOERROR;
191}
192
193static s16_t
194snmp_scalar_array_get_value(struct snmp_node_instance* instance, void* value)
195{
196  const struct snmp_scalar_array_node* array_node = (const struct snmp_scalar_array_node*)(const void*)instance->node;
197  const struct snmp_scalar_array_node_def* array_node_def = (const struct snmp_scalar_array_node_def*)instance->reference.const_ptr;
198
199  return array_node->get_value(array_node_def, value);
200}
201
202static snmp_err_t
203snmp_scalar_array_set_test(struct snmp_node_instance* instance, u16_t value_len, void* value)
204{
205  const struct snmp_scalar_array_node* array_node = (const struct snmp_scalar_array_node*)(const void*)instance->node;
206  const struct snmp_scalar_array_node_def* array_node_def = (const struct snmp_scalar_array_node_def*)instance->reference.const_ptr;
207
208  return array_node->set_test(array_node_def, value_len, value);
209}
210
211static snmp_err_t
212snmp_scalar_array_set_value(struct snmp_node_instance* instance, u16_t value_len, void* value)
213{
214  const struct snmp_scalar_array_node* array_node = (const struct snmp_scalar_array_node*)(const void*)instance->node;
215  const struct snmp_scalar_array_node_def* array_node_def = (const struct snmp_scalar_array_node_def*)instance->reference.const_ptr;
216
217  return array_node->set_value(array_node_def, value_len, value);
218}
219
220#endif /* LWIP_SNMP */
221