blob: 3961fc075d6c92ec028d10179811f5c6037ce96f [file] [log] [blame]
/*
* libjingle
* Copyright 2008, Google Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "talk/base/nethelpers.h"
#include "talk/base/byteorder.h"
#include "talk/base/signalthread.h"
namespace talk_base {
#if defined(LINUX) || defined(ANDROID)
static const size_t kInitHostentLen = 1024;
static const size_t kMaxHostentLen = kInitHostentLen * 8;
#endif
// AsyncResolver
AsyncResolver::AsyncResolver() : result_(NULL), error_(0) {
}
AsyncResolver::~AsyncResolver() {
FreeHostEnt(result_);
}
void AsyncResolver::DoWork() {
result_ = SafeGetHostByName(addr_.hostname().c_str(), &error_);
}
void AsyncResolver::OnWorkDone() {
if (result_) {
addr_.SetIP(NetworkToHost32(
*reinterpret_cast<uint32*>(result_->h_addr_list[0])));
}
}
#if defined(WIN32) || defined(ANDROID) || defined(OPENBSD)
static hostent* DeepCopyHostent(const hostent* ent) {
// Get the total number of bytes we need to copy, and allocate our buffer.
int num_aliases = 0, num_addrs = 0;
int total_len = sizeof(hostent);
total_len += strlen(ent->h_name) + 1;
while (ent->h_aliases[num_aliases]) {
total_len += sizeof(char*) + strlen(ent->h_aliases[num_aliases]) + 1;
++num_aliases;
}
total_len += sizeof(char*);
while (ent->h_addr_list[num_addrs]) {
total_len += sizeof(char*) + ent->h_length;
++num_addrs;
}
total_len += sizeof(char*);
hostent* result = static_cast<hostent*>(malloc(total_len));
if (NULL == result) {
return NULL;
}
char* p = reinterpret_cast<char*>(result) + sizeof(hostent);
// Copy the hostent into it, along with its embedded pointers.
result->h_name = p;
memcpy(p, ent->h_name, strlen(ent->h_name) + 1);
p += strlen(ent->h_name) + 1;
result->h_aliases = reinterpret_cast<char**>(p);
p += (num_aliases + 1) * sizeof(char*);
for (int i = 0; i < num_aliases; ++i) {
result->h_aliases[i] = p;
memcpy(p, ent->h_aliases[i], strlen(ent->h_aliases[i]) + 1);
p += strlen(ent->h_aliases[i]) + 1;
}
result->h_aliases[num_aliases] = NULL;
result->h_addrtype = ent->h_addrtype;
result->h_length = ent->h_length;
result->h_addr_list = reinterpret_cast<char**>(p);
p += (num_addrs + 1) * sizeof(char*);
for (int i = 0; i < num_addrs; ++i) {
result->h_addr_list[i] = p;
memcpy(p, ent->h_addr_list[i], ent->h_length);
p += ent->h_length;
}
result->h_addr_list[num_addrs] = NULL;
return result;
}
#endif
// The functions below are used to do gethostbyname, but with an allocated
// instead of a static buffer.
hostent* SafeGetHostByName(const char* hostname, int* herrno) {
if (NULL == hostname || NULL == herrno) {
return NULL;
}
hostent* result = NULL;
#if defined(WIN32)
// On Windows we have to allocate a buffer, and manually copy the hostent,
// along with its embedded pointers.
hostent* ent = gethostbyname(hostname);
if (!ent) {
*herrno = WSAGetLastError();
return NULL;
}
result = DeepCopyHostent(ent);
*herrno = 0;
#elif defined(LINUX) || defined(ANDROID)
// gethostbyname() is not thread safe, so we need to call gethostbyname_r()
// which is a reentrant version of gethostbyname().
ASSERT(kInitHostentLen > sizeof(hostent));
size_t size = kInitHostentLen;
int ret;
void* buf = malloc(size);
if (NULL == buf) {
return NULL;
}
char* aux = static_cast<char*>(buf) + sizeof(hostent);
size_t aux_len = size - sizeof(hostent);
while ((ret = gethostbyname_r(hostname, reinterpret_cast<hostent*>(buf), aux,
aux_len, &result, herrno)) == ERANGE) {
size *= 2;
if (size > kMaxHostentLen) {
break; // Just to be safe.
}
buf = realloc(buf, size);
if (NULL == buf) {
return NULL;
}
aux = static_cast<char*>(buf) + sizeof(hostent);
aux_len = size - sizeof(hostent);
}
if (ret != 0 || buf != result) {
free(buf);
return NULL;
}
#if defined(ANDROID)
// Note that Android's version of gethostbyname_r has a bug such that the
// returned hostent contains pointers into thread-local storage. (See bug
// 4383723.) So we deep copy the result before returning.
hostent* deep_copy = DeepCopyHostent(result);
FreeHostEnt(result);
result = deep_copy;
#endif
*herrno = 0;
#elif defined(OSX) || defined(IOS) || defined(FREEBSD)
// Mac OS returns an object with everything allocated.
result = getipnodebyname(hostname, AF_INET, AI_DEFAULT, herrno);
#elif defined(OPENBSD)
hostent* ent = gethostbyname(hostname);
if (!ent) {
return NULL;
}
result = DeepCopyHostent(ent);
*herrno = 0;
#else
#error "I don't know how to do gethostbyname safely on your system."
#endif
return result;
}
// This function should mirror the above function, and free any resources
// allocated by the above.
void FreeHostEnt(hostent* host) {
#if defined(OSX) || defined(IOS) || defined(FREEBSD)
freehostent(host);
#elif defined(WIN32) || defined(POSIX)
free(host);
#else
#error "I don't know how to free a hostent on your system."
#endif
}
const char* inet_ntop(int af, const void *src, char* dst, socklen_t size) {
#ifdef WIN32
return win32_inet_ntop(af, src, dst, size);
#else
return ::inet_ntop(af, src, dst, size);
#endif
}
int inet_pton(int af, const char* src, void *dst) {
#ifdef WIN32
return win32_inet_pton(af, src, dst);
#else
return ::inet_pton(af, src, dst);
#endif
}
} // namespace talk_base