1/**
2 * @file
3 * Common functions used throughout the stack.
4 *
5 * These are reference implementations of the byte swapping functions.
6 * Again with the aim of being simple, correct and fully portable.
7 * Byte swapping is the second thing you would want to optimize. You will
8 * need to port it to your architecture and in your cc.h:
9 *
10 * \#define lwip_htons(x) your_htons
11 * \#define lwip_htonl(x) your_htonl
12 *
13 * Note lwip_ntohs() and lwip_ntohl() are merely references to the htonx counterparts.
14 *
15 * If you \#define them to htons() and htonl(), you should
16 * \#define LWIP_DONT_PROVIDE_BYTEORDER_FUNCTIONS to prevent lwIP from
17 * defining htonx/ntohx compatibility macros.
18
19 * @defgroup sys_nonstandard Non-standard functions
20 * @ingroup sys_layer
21 * lwIP provides default implementations for non-standard functions.
22 * These can be mapped to OS functions to reduce code footprint if desired.
23 * All defines related to this section must not be placed in lwipopts.h,
24 * but in arch/cc.h!
25 * These options cannot be \#defined in lwipopts.h since they are not options
26 * of lwIP itself, but options of the lwIP port to your system.
27 */
28
29/*
30 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
31 * All rights reserved.
32 *
33 * Redistribution and use in source and binary forms, with or without modification,
34 * are permitted provided that the following conditions are met:
35 *
36 * 1. Redistributions of source code must retain the above copyright notice,
37 *    this list of conditions and the following disclaimer.
38 * 2. Redistributions in binary form must reproduce the above copyright notice,
39 *    this list of conditions and the following disclaimer in the documentation
40 *    and/or other materials provided with the distribution.
41 * 3. The name of the author may not be used to endorse or promote products
42 *    derived from this software without specific prior written permission.
43 *
44 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
45 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
46 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
47 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
48 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
49 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
50 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
51 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
52 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
53 * OF SUCH DAMAGE.
54 *
55 * This file is part of the lwIP TCP/IP stack.
56 *
57 * Author: Simon Goldschmidt
58 *
59 */
60
61#include "lwip/opt.h"
62#include "lwip/def.h"
63
64#include <string.h>
65
66#if BYTE_ORDER == LITTLE_ENDIAN
67
68#if !defined(lwip_htons)
69/**
70 * Convert an u16_t from host- to network byte order.
71 *
72 * @param n u16_t in host byte order
73 * @return n in network byte order
74 */
75u16_t
76lwip_htons(u16_t n)
77{
78  return PP_HTONS(n);
79}
80#endif /* lwip_htons */
81
82#if !defined(lwip_htonl)
83/**
84 * Convert an u32_t from host- to network byte order.
85 *
86 * @param n u32_t in host byte order
87 * @return n in network byte order
88 */
89u32_t
90lwip_htonl(u32_t n)
91{
92  return PP_HTONL(n);
93}
94#endif /* lwip_htonl */
95
96#endif /* BYTE_ORDER == LITTLE_ENDIAN */
97
98#ifndef lwip_strnstr
99/**
100 * @ingroup sys_nonstandard
101 * lwIP default implementation for strnstr() non-standard function.
102 * This can be \#defined to strnstr() depending on your platform port.
103 */
104char *
105lwip_strnstr(const char *buffer, const char *token, size_t n)
106{
107  const char *p;
108  size_t tokenlen = strlen(token);
109  if (tokenlen == 0) {
110    return LWIP_CONST_CAST(char *, buffer);
111  }
112  for (p = buffer; *p && (p + tokenlen <= buffer + n); p++) {
113    if ((*p == *token) && (strncmp(p, token, tokenlen) == 0)) {
114      return LWIP_CONST_CAST(char *, p);
115    }
116  }
117  return NULL;
118}
119#endif
120
121#ifndef lwip_stricmp
122/**
123 * @ingroup sys_nonstandard
124 * lwIP default implementation for stricmp() non-standard function.
125 * This can be \#defined to stricmp() depending on your platform port.
126 */
127int
128lwip_stricmp(const char *str1, const char *str2)
129{
130  char c1, c2;
131
132  do {
133    c1 = *str1++;
134    c2 = *str2++;
135    if (c1 != c2) {
136      char c1_upc = c1 | 0x20;
137      if ((c1_upc >= 'a') && (c1_upc <= 'z')) {
138        /* characters are not equal an one is in the alphabet range:
139        downcase both chars and check again */
140        char c2_upc = c2 | 0x20;
141        if (c1_upc != c2_upc) {
142          /* still not equal */
143          /* don't care for < or > */
144          return 1;
145        }
146      } else {
147        /* characters are not equal but none is in the alphabet range */
148        return 1;
149      }
150    }
151  } while (c1 != 0);
152  return 0;
153}
154#endif
155
156#ifndef lwip_strnicmp
157/**
158 * @ingroup sys_nonstandard
159 * lwIP default implementation for strnicmp() non-standard function.
160 * This can be \#defined to strnicmp() depending on your platform port.
161 */
162int
163lwip_strnicmp(const char *str1, const char *str2, size_t len)
164{
165  char c1, c2;
166
167  do {
168    c1 = *str1++;
169    c2 = *str2++;
170    if (c1 != c2) {
171      char c1_upc = c1 | 0x20;
172      if ((c1_upc >= 'a') && (c1_upc <= 'z')) {
173        /* characters are not equal an one is in the alphabet range:
174        downcase both chars and check again */
175        char c2_upc = c2 | 0x20;
176        if (c1_upc != c2_upc) {
177          /* still not equal */
178          /* don't care for < or > */
179          return 1;
180        }
181      } else {
182        /* characters are not equal but none is in the alphabet range */
183        return 1;
184      }
185    }
186    len--;
187  } while ((len != 0) && (c1 != 0));
188  return 0;
189}
190#endif
191
192#ifndef lwip_itoa
193/**
194 * @ingroup sys_nonstandard
195 * lwIP default implementation for itoa() non-standard function.
196 * This can be \#defined to itoa() or snprintf(result, bufsize, "%d", number) depending on your platform port.
197 */
198void
199lwip_itoa(char *result, size_t bufsize, int number)
200{
201  char *res = result;
202  char *tmp = result + bufsize - 1;
203  int n = (number >= 0) ? number : -number;
204
205  /* handle invalid bufsize */
206  if (bufsize < 2) {
207    if (bufsize == 1) {
208      *result = 0;
209    }
210    return;
211  }
212
213  /* First, add sign */
214  if (number < 0) {
215    *res++ = '-';
216  }
217  /* Then create the string from the end and stop if buffer full,
218     and ensure output string is zero terminated */
219  *tmp = 0;
220  while ((n != 0) && (tmp > res)) {
221    char val = (char)('0' + (n % 10));
222    tmp--;
223    *tmp = val;
224    n = n / 10;
225  }
226  if (n) {
227    /* buffer is too small */
228    *result = 0;
229    return;
230  }
231  if (*tmp == 0) {
232    /* Nothing added? */
233    *res++ = '0';
234    *res++ = 0;
235    return;
236  }
237  /* move from temporary buffer to output buffer (sign is not moved) */
238  memmove(res, tmp, (size_t)((result + bufsize) - tmp));
239}
240#endif
241