ZeroTierOne/node/HttpClient.cpp
2013-12-12 11:33:41 -08:00

312 lines
8.9 KiB
C++

/*
* ZeroTier One - Global Peer to Peer Ethernet
* Copyright (C) 2012-2013 ZeroTier Networks LLC
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* --
*
* ZeroTier may be used and distributed under the terms of the GPLv3, which
* are available at: http://www.gnu.org/licenses/gpl-3.0.html
*
* If you would like to embed ZeroTier into a commercial application or
* redistribute it in a modified binary form, please contact ZeroTier Networks
* LLC. Start here: http://www.zerotier.com/
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <vector>
#include <utility>
#include <algorithm>
#include "Constants.hpp"
#include "HttpClient.hpp"
#include "Thread.hpp"
#include "Utils.hpp"
#include "NonCopyable.hpp"
#include "Defaults.hpp"
#ifdef __UNIX_LIKE__
#include <unistd.h>
#include <signal.h>
#include <fcntl.h>
#include <sys/select.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/wait.h>
#endif
namespace ZeroTier {
const std::map<std::string,std::string> HttpClient::NO_HEADERS;
#ifdef __UNIX_LIKE__
// The *nix implementation calls 'curl' externally rather than linking to it.
// This makes it an optional dependency that can be avoided in tiny systems
// provided you don't want to have automatic software updates... or want to
// do them via another method.
#ifdef __APPLE__
// TODO: get proxy configuration
#endif
// Paths where "curl" may be found on the system
#define NUM_CURL_PATHS 5
static const char *CURL_PATHS[NUM_CURL_PATHS] = { "/usr/bin/curl","/bin/curl","/usr/local/bin/curl","/usr/sbin/curl","/sbin/curl" };
// Maximum message length
#define CURL_MAX_MESSAGE_LENGTH (1024 * 1024 * 64)
// Internal private thread class that performs request, notifies handler,
// and then commits suicide by deleting itself.
class P_Req : NonCopyable
{
public:
P_Req(const char *method,const std::string &url,const std::map<std::string,std::string> &headers,unsigned int timeout,void (*handler)(void *,int,const std::string &,bool,const std::string &),void *arg) :
_url(url),
_headers(headers),
_timeout(timeout),
_handler(handler),
_arg(arg)
{
_myThread = Thread::start(this);
}
void threadMain()
{
char *curlArgs[1024];
char buf[16384];
fd_set readfds,writefds,errfds;
struct timeval tv;
std::string curlPath;
for(int i=0;i<NUM_CURL_PATHS;++i) {
if (Utils::fileExists(CURL_PATHS[i])) {
curlPath = CURL_PATHS[i];
break;
}
}
if (!curlPath.length()) {
_handler(_arg,-1,_url,false,"unable to locate 'curl' binary in /usr/bin, /bin, /usr/local/bin, /usr/sbin, or /sbin");
delete this;
return;
}
if (!_url.length()) {
_handler(_arg,-1,_url,false,"cannot fetch empty URL");
delete this;
return;
}
curlArgs[0] = const_cast <char *>(curlPath.c_str());
curlArgs[1] = const_cast <char *>("-D");
curlArgs[2] = const_cast <char *>("-"); // append headers before output
int argPtr = 3;
std::vector<std::string> headerArgs;
for(std::map<std::string,std::string>::const_iterator h(_headers.begin());h!=_headers.end();++h) {
headerArgs.push_back(h->first);
headerArgs.back().append(": ");
headerArgs.back().append(h->second);
}
for(std::vector<std::string>::iterator h(headerArgs.begin());h!=headerArgs.end();++h) {
if (argPtr >= (1024 - 4)) // leave room for terminating NULL and URL
break;
curlArgs[argPtr++] = const_cast <char *>("-H");
curlArgs[argPtr++] = const_cast <char *>(h->c_str());
}
curlArgs[argPtr++] = const_cast <char *>(_url.c_str());
curlArgs[argPtr] = (char *)0;
int curlStdout[2];
int curlStderr[2];
::pipe(curlStdout);
::pipe(curlStderr);
long pid = (long)vfork();
if (pid < 0) {
// fork() failed
::close(curlStdout[0]);
::close(curlStdout[1]);
::close(curlStderr[0]);
::close(curlStderr[1]);
_handler(_arg,-1,_url,false,"unable to fork()");
delete this;
return;
} else if (pid > 0) {
// fork() succeeded, in parent process
::close(curlStdout[1]);
::close(curlStderr[1]);
fcntl(curlStdout[0],F_SETFL,O_NONBLOCK);
fcntl(curlStderr[0],F_SETFL,O_NONBLOCK);
int exitCode = -1;
unsigned long long timesOutAt = Utils::now() + ((unsigned long long)_timeout * 1000ULL);
bool timedOut = false;
bool tooLong = false;
for(;;) {
FD_ZERO(&readfds);
FD_ZERO(&writefds);
FD_ZERO(&errfds);
FD_SET(curlStdout[0],&readfds);
FD_SET(curlStderr[0],&readfds);
FD_SET(curlStdout[0],&errfds);
FD_SET(curlStderr[0],&errfds);
tv.tv_sec = 1;
tv.tv_usec = 0;
select(std::max(curlStdout[0],curlStderr[0])+1,&readfds,&writefds,&errfds,&tv);
if (FD_ISSET(curlStdout[0],&readfds)) {
int n = (int)::read(curlStdout[0],buf,sizeof(buf));
if (n > 0) {
_body.append(buf,n);
// Reset timeout when data is read...
timesOutAt = Utils::now() + ((unsigned long long)_timeout * 1000ULL);
} else if (n < 0)
break;
if (_body.length() > CURL_MAX_MESSAGE_LENGTH) {
::kill(pid,SIGKILL);
tooLong = true;
break;
}
}
if (FD_ISSET(curlStderr[0],&readfds))
::read(curlStderr[0],buf,sizeof(buf));
if (FD_ISSET(curlStdout[0],&errfds)||FD_ISSET(curlStderr[0],&errfds))
break;
if (Utils::now() >= timesOutAt) {
::kill(pid,SIGKILL);
timedOut = true;
break;
}
if (waitpid(pid,&exitCode,WNOHANG) > 0) {
for(;;) {
// Drain output...
int n = (int)::read(curlStdout[0],buf,sizeof(buf));
if (n <= 0)
break;
else {
_body.append(buf,n);
if (_body.length() > CURL_MAX_MESSAGE_LENGTH) {
tooLong = true;
break;
}
}
}
pid = 0;
break;
}
}
if (pid > 0)
waitpid(pid,&exitCode,0);
::close(curlStdout[0]);
::close(curlStderr[0]);
if (timedOut)
_handler(_arg,-1,_url,false,"connection timed out");
else if (tooLong)
_handler(_arg,-1,_url,false,"response too long");
else if (exitCode)
_handler(_arg,-1,_url,false,"connection failed (curl returned non-zero exit code)");
else {
unsigned long idx = 0;
// Grab status line and headers, which will prefix output on
// success and will end with an empty line.
std::vector<std::string> headers;
headers.push_back(std::string());
while (idx < _body.length()) {
char c = _body[idx++];
if (c == '\n') {
if (!headers.back().length()) {
headers.pop_back();
break;
} else headers.push_back(std::string());
} else if (c != '\r')
headers.back().push_back(c);
}
if (headers.empty()||(!headers.front().length())) {
_handler(_arg,-1,_url,false,"HTTP response empty");
delete this;
return;
}
// Parse first line -- HTTP status code and response
size_t scPos = headers.front().find(' ');
if (scPos == std::string::npos) {
_handler(_arg,-1,_url,false,"invalid HTTP response (no status line)");
delete this;
return;
}
++scPos;
unsigned int rcode = Utils::strToUInt(headers.front().substr(scPos,3).c_str());
if ((!rcode)||(rcode > 999)) {
_handler(_arg,-1,_url,false,"invalid HTTP response (invalid response code)");
delete this;
return;
}
// Serve up the resulting data to the handler
if (rcode == 200)
_handler(_arg,rcode,_url,false,_body.substr(idx));
else if ((scPos + 4) < headers.front().length())
_handler(_arg,rcode,_url,false,headers.front().substr(scPos+4));
else _handler(_arg,rcode,_url,false,"(no status message from server)");
}
delete this;
return;
} else {
// fork() succeeded, in child process
::dup2(curlStdout[1],STDOUT_FILENO);
::close(curlStdout[1]);
::dup2(curlStderr[1],STDERR_FILENO);
::close(curlStderr[1]);
::execv(curlPath.c_str(),curlArgs);
::exit(-1); // only reached if execv() fails
}
}
const std::string _url;
std::string _body;
std::map<std::string,std::string> _headers;
unsigned int _timeout;
void (*_handler)(void *,int,const std::string &,bool,const std::string &);
void *_arg;
Thread _myThread;
};
HttpClient::Request HttpClient::_do(
const char *method,
const std::string &url,
const std::map<std::string,std::string> &headers,
unsigned int timeout,
void (*handler)(void *,int,const std::string &,bool,const std::string &),
void *arg)
{
return (HttpClient::Request)(new P_Req(method,url,headers,timeout,handler,arg));
}
#endif
} // namespace ZeroTier