mDNSShared/dnssd_ipc.c

   1 /*
   2  * Copyright (c) 2003-2019 Apple Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions are met:
   6  *
   7  * 1.  Redistributions of source code must retain the above copyright notice,
   8  *     this list of conditions and the following disclaimer.
   9  * 2.  Redistributions in binary form must reproduce the above copyright notice,
  10  *     this list of conditions and the following disclaimer in the documentation
  11  *     and/or other materials provided with the distribution.
  12  * 3.  Neither the name of Apple Inc. ("Apple") nor the names of its
  13  *     contributors may be used to endorse or promote products derived from this
  14  *     software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
  17  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  18  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  19  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
  20  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  21  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  22  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  23  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  25  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26  */
  27
  28 #include "dnssd_ipc.h"
  29
  30 #if defined(_WIN32)
  31
  32 char *win32_strerror(int inErrorCode)
  33 {
  34     static char buffer[1024];
  35     DWORD n;
  36     memset(buffer, 0, sizeof(buffer));
  37     n = FormatMessageA(
  38         FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
  39         NULL,
  40         (DWORD) inErrorCode,
  41         MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
  42         buffer,
  43         sizeof(buffer),
  44         NULL);
  45     if (n > 0)
  46     {
  47         // Remove any trailing CR's or LF's since some messages have them.
  48         while ((n > 0) && isspace(((unsigned char *) buffer)[n - 1]))
  49             buffer[--n] = '\0';
  50     }
  51     return buffer;
  52 }
  53
  54 #endif
  55
  56 void put_uint32(const uint32_t l, char **ptr)
  57 {
  58     (*ptr)[0] = (char)((l >> 24) &  0xFF);
  59     (*ptr)[1] = (char)((l >> 16) &  0xFF);
  60     (*ptr)[2] = (char)((l >>  8) &  0xFF);
  61     (*ptr)[3] = (char)((l      ) &  0xFF);
  62     *ptr += sizeof(uint32_t);
  63 }
  64
  65 uint32_t get_uint32(const char **ptr, const char *end)
  66 {
  67     if (!*ptr || *ptr + sizeof(uint32_t) > end)
  68     {
  69         *ptr = NULL;
  70         return(0);
  71     }
  72     else
  73     {
  74         uint8_t *p = (uint8_t*) *ptr;
  75         *ptr += sizeof(uint32_t);
  76         return((uint32_t) ((uint32_t)p[0] << 24 | (uint32_t)p[1] << 16 | (uint32_t)p[2] << 8 | p[3]));
  77     }
  78 }
  79
  80 void put_uint16(uint16_t s, char **ptr)
  81 {
  82     (*ptr)[0] = (char)((s >>  8) &  0xFF);
  83     (*ptr)[1] = (char)((s      ) &  0xFF);
  84     *ptr += sizeof(uint16_t);
  85 }
  86
  87 uint16_t get_uint16(const char **ptr, const char *end)
  88 {
  89     if (!*ptr || *ptr + sizeof(uint16_t) > end)
  90     {
  91         *ptr = NULL;
  92         return(0);
  93     }
  94     else
  95     {
  96         uint8_t *p = (uint8_t*) *ptr;
  97         *ptr += sizeof(uint16_t);
  98         return((uint16_t) ((uint16_t)p[0] << 8 | p[1]));
  99     }
 100 }
 101
 102 int put_string(const char *str, char **ptr)
 103 {
 104     size_t len;
 105     if (!str) str = "";
 106     len = strlen(str) + 1;
 107     memcpy(*ptr, str, len);
 108     *ptr += len;
 109     return 0;
 110 }
 111
 112 int get_string(const char **ptr, const char *const end, char *buffer, int buflen)
 113 {
 114     if (!*ptr)
 115     {
 116         *buffer = 0;
 117         return(-1);
 118     }
 119     else
 120     {
 121         char *lim = buffer + buflen;    // Calculate limit
 122         while (*ptr < end && buffer < lim)
 123         {
 124             char c = *buffer++ = *(*ptr)++;
 125             if (c == 0) return(0);      // Success
 126         }
 127         if (buffer == lim) buffer--;
 128         *buffer = 0;                    // Failed, so terminate string,
 129         *ptr = NULL;                    // clear pointer,
 130         return(-1);                     // and return failure indication
 131     }
 132 }
 133
 134 void put_rdata(const int rdlen, const unsigned char *rdata, char **ptr)
 135 {
 136     memcpy(*ptr, rdata, rdlen);
 137     *ptr += rdlen;
 138 }
 139
 140 const char *get_rdata(const char **ptr, const char *end, int rdlen)
 141 {
 142     if (!*ptr || *ptr + rdlen > end)
 143     {
 144         *ptr = NULL;
 145         return(0);
 146     }
 147     else
 148     {
 149         const char *rd = *ptr;
 150         *ptr += rdlen;
 151         return rd;
 152     }
 153 }
 154
 155 void ConvertHeaderBytes(ipc_msg_hdr *hdr)
 156 {
 157     hdr->version   = htonl(hdr->version);
 158     hdr->datalen   = htonl(hdr->datalen);
 159     hdr->ipc_flags = htonl(hdr->ipc_flags);
 160     hdr->op        = htonl(hdr->op );
 161     hdr->reg_index = htonl(hdr->reg_index);
 162 }