A C library for asynchronous DNS requests (grpc依赖)
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/* MIT License
*
* Copyright (c) The c-ares project and its contributors
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
* SPDX-License-Identifier: MIT
*/
#include "ares_setup.h"
#include "ares.h"
#include "ares_nameser.h"
#include "ares-test.h"
#include "ares-test-ai.h"
#include "dns-proto.h"
#include "ares_dns.h"
extern "C" {
// Remove command-line defines of package variables for the test project...
#undef PACKAGE_NAME
#undef PACKAGE_BUGREPORT
#undef PACKAGE_STRING
#undef PACKAGE_TARNAME
// ... so we can include the library's config without symbol redefinitions.
#include "ares_setup.h"
#include "ares_inet_net_pton.h"
#include "ares_data.h"
#include "str/ares_strsplit.h"
#include "ares_private.h"
}
#ifdef HAVE_NETDB_H
#include <netdb.h>
#endif
#ifdef HAVE_NETINET_TCP_H
#include <netinet/tcp.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <functional>
#include <sstream>
#include <algorithm>
#include <chrono>
#ifdef WIN32
#define BYTE_CAST (char *)
#define mkdir_(d, p) mkdir(d)
#else
#define BYTE_CAST
#define mkdir_(d, p) mkdir(d, p)
#endif
namespace ares {
namespace test {
bool verbose = false;
static constexpr unsigned short dynamic_port = 0;
unsigned short mock_port = dynamic_port;
const std::vector<int> both_families = {AF_INET, AF_INET6};
const std::vector<int> ipv4_family = {AF_INET};
const std::vector<int> ipv6_family = {AF_INET6};
const std::vector<std::pair<int, bool>> both_families_both_modes = {
std::make_pair<int, bool>(AF_INET, false),
std::make_pair<int, bool>(AF_INET, true),
std::make_pair<int, bool>(AF_INET6, false),
std::make_pair<int, bool>(AF_INET6, true)
};
const std::vector<std::pair<int, bool>> ipv4_family_both_modes = {
std::make_pair<int, bool>(AF_INET, false),
std::make_pair<int, bool>(AF_INET, true)
};
const std::vector<std::pair<int, bool>> ipv6_family_both_modes = {
std::make_pair<int, bool>(AF_INET6, false),
std::make_pair<int, bool>(AF_INET6, true)
};
const std::vector<std::tuple<ares_evsys_t, int, bool>> all_evsys_ipv4_family_both_modes = {
#ifdef _WIN32
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_WIN32, AF_INET, false),
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_WIN32, AF_INET, true),
#endif
#ifdef HAVE_KQUEUE
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_KQUEUE, AF_INET, false),
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_KQUEUE, AF_INET, true),
#endif
#ifdef HAVE_EPOLL
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_EPOLL, AF_INET, false),
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_EPOLL, AF_INET, true),
#endif
#ifdef HAVE_POLL
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_POLL, AF_INET, false),
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_POLL, AF_INET, true),
#endif
#ifdef HAVE_PIPE
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_SELECT, AF_INET, false),
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_SELECT, AF_INET, true),
#endif
};
const std::vector<std::tuple<ares_evsys_t, int, bool>> all_evsys_ipv6_family_both_modes = {
#ifdef _WIN32
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_WIN32, AF_INET6, false),
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_WIN32, AF_INET6, true),
#endif
#ifdef HAVE_KQUEUE
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_KQUEUE, AF_INET6, false),
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_KQUEUE, AF_INET6, true),
#endif
#ifdef HAVE_EPOLL
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_EPOLL, AF_INET6, false),
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_EPOLL, AF_INET6, true),
#endif
#ifdef HAVE_POLL
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_POLL, AF_INET6, false),
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_POLL, AF_INET6, true),
#endif
#ifdef HAVE_PIPE
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_SELECT, AF_INET6, false),
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_SELECT, AF_INET6, true),
#endif
};
const std::vector<std::tuple<ares_evsys_t, int, bool>> all_evsys_both_families_both_modes = {
#ifdef _WIN32
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_WIN32, AF_INET, false),
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_WIN32, AF_INET, true),
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_WIN32, AF_INET6, false),
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_WIN32, AF_INET6, true),
#endif
#ifdef HAVE_KQUEUE
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_KQUEUE, AF_INET, false),
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_KQUEUE, AF_INET, true),
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_KQUEUE, AF_INET6, false),
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_KQUEUE, AF_INET6, true),
#endif
#ifdef HAVE_EPOLL
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_EPOLL, AF_INET, false),
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_EPOLL, AF_INET, true),
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_EPOLL, AF_INET6, false),
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_EPOLL, AF_INET6, true),
#endif
#ifdef HAVE_POLL
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_POLL, AF_INET, false),
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_POLL, AF_INET, true),
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_POLL, AF_INET6, false),
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_POLL, AF_INET6, true),
#endif
#ifdef HAVE_PIPE
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_SELECT, AF_INET, false),
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_SELECT, AF_INET, true),
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_SELECT, AF_INET6, false),
std::make_tuple<ares_evsys_t, int, bool>(ARES_EVSYS_SELECT, AF_INET6, true),
#endif
};
std::vector<std::tuple<ares_evsys_t, int, bool>> evsys_families_modes = all_evsys_both_families_both_modes;
const std::vector<std::tuple<ares_evsys_t, int>> all_evsys_ipv4_family = {
#ifdef _WIN32
std::make_tuple<ares_evsys_t, int>(ARES_EVSYS_WIN32, AF_INET),
#endif
#ifdef HAVE_KQUEUE
std::make_tuple<ares_evsys_t, int>(ARES_EVSYS_KQUEUE, AF_INET),
#endif
#ifdef HAVE_EPOLL
std::make_tuple<ares_evsys_t, int>(ARES_EVSYS_EPOLL, AF_INET),
#endif
#ifdef HAVE_POLL
std::make_tuple<ares_evsys_t, int>(ARES_EVSYS_POLL, AF_INET),
#endif
#ifdef HAVE_PIPE
std::make_tuple<ares_evsys_t, int>(ARES_EVSYS_SELECT, AF_INET),
#endif
};
const std::vector<std::tuple<ares_evsys_t, int>> all_evsys_ipv6_family = {
#ifdef _WIN32
std::make_tuple<ares_evsys_t, int>(ARES_EVSYS_WIN32, AF_INET6),
#endif
#ifdef HAVE_KQUEUE
std::make_tuple<ares_evsys_t, int>(ARES_EVSYS_KQUEUE, AF_INET6),
#endif
#ifdef HAVE_EPOLL
std::make_tuple<ares_evsys_t, int>(ARES_EVSYS_EPOLL, AF_INET6),
#endif
#ifdef HAVE_POLL
std::make_tuple<ares_evsys_t, int>(ARES_EVSYS_POLL, AF_INET6),
#endif
#ifdef HAVE_PIPE
std::make_tuple<ares_evsys_t, int>(ARES_EVSYS_SELECT, AF_INET6),
#endif
};
const std::vector<std::tuple<ares_evsys_t, int>> all_evsys_both_families = {
#ifdef _WIN32
std::make_tuple<ares_evsys_t, int>(ARES_EVSYS_WIN32, AF_INET),
std::make_tuple<ares_evsys_t, int>(ARES_EVSYS_WIN32, AF_INET6),
#endif
#ifdef HAVE_KQUEUE
std::make_tuple<ares_evsys_t, int>(ARES_EVSYS_KQUEUE, AF_INET),
std::make_tuple<ares_evsys_t, int>(ARES_EVSYS_KQUEUE, AF_INET6),
#endif
#ifdef HAVE_EPOLL
std::make_tuple<ares_evsys_t, int>(ARES_EVSYS_EPOLL, AF_INET),
std::make_tuple<ares_evsys_t, int>(ARES_EVSYS_EPOLL, AF_INET6),
#endif
#ifdef HAVE_POLL
std::make_tuple<ares_evsys_t, int>(ARES_EVSYS_POLL, AF_INET),
std::make_tuple<ares_evsys_t, int>(ARES_EVSYS_POLL, AF_INET6),
#endif
#ifdef HAVE_PIPE
std::make_tuple<ares_evsys_t, int>(ARES_EVSYS_SELECT, AF_INET),
std::make_tuple<ares_evsys_t, int>(ARES_EVSYS_SELECT, AF_INET6),
#endif
};
std::vector<std::tuple<ares_evsys_t, int>> evsys_families = all_evsys_both_families;
// Which parameters to use in tests
std::vector<int> families = both_families;
std::vector<std::pair<int, bool>> families_modes = both_families_both_modes;
unsigned long long LibraryTest::fails_ = 0;
std::map<size_t, int> LibraryTest::size_fails_;
std::mutex LibraryTest::lock_;
void ares_sleep_time(unsigned int ms)
{
auto duration = std::chrono::milliseconds(ms);
auto start_time = std::chrono::high_resolution_clock::now();
auto wake_time = start_time + duration;
std::this_thread::sleep_until(wake_time);
auto end_time = std::chrono::high_resolution_clock::now();
if (verbose) std::cerr << "sleep requested " << ms << "ms, slept for " << std::chrono::duration_cast<std::chrono::milliseconds>(end_time - start_time).count() << "ms" << std::endl;
}
void ProcessWork(ares_channel_t *channel,
std::function<std::set<ares_socket_t>()> get_extrafds,
std::function<void(ares_socket_t)> process_extra,
unsigned int cancel_ms) {
int nfds, count;
fd_set readers, writers;
auto tv_begin = std::chrono::high_resolution_clock::now();
auto tv_cancel = tv_begin;
if (cancel_ms) {
if (verbose) std::cerr << "ares_cancel will be called after " << cancel_ms << "ms" << std::endl;
tv_cancel += std::chrono::milliseconds(cancel_ms);
}
while (true) {
struct timeval tv;
struct timeval *tv_select;
// Retrieve the set of file descriptors that the library wants us to monitor.
FD_ZERO(&readers);
FD_ZERO(&writers);
nfds = ares_fds(channel, &readers, &writers);
if (nfds == 0) // no work left to do in the library
return;
// Add in the extra FDs if present.
std::set<ares_socket_t> extrafds = get_extrafds();
for (ares_socket_t extrafd : extrafds) {
FD_SET(extrafd, &readers);
if (extrafd >= (ares_socket_t)nfds) {
nfds = (int)extrafd + 1;
}
}
/* If ares_timeout returns NULL, it means there are no requests in queue,
* so we can break out */
tv_select = ares_timeout(channel, NULL, &tv);
if (tv_select == NULL)
return;
if (cancel_ms) {
auto tv_now = std::chrono::high_resolution_clock::now();
auto remaining_ms = std::chrono::duration_cast<std::chrono::milliseconds>(tv_cancel - tv_now).count();
if (remaining_ms <= 0) {
if (verbose) std::cerr << "Issuing ares_cancel()" << std::endl;
ares_cancel(channel);
cancel_ms = 0; /* Disable issuing cancel again */
} else {
struct timeval tv_remaining;
tv_remaining.tv_sec = remaining_ms / 1000;
tv_remaining.tv_usec = (int)(remaining_ms % 1000);
/* Recalculate proper timeout since we also have a cancel to wait on */
tv_select = ares_timeout(channel, &tv_remaining, &tv);
}
}
count = select(nfds, &readers, &writers, nullptr, tv_select);
if (count < 0) {
fprintf(stderr, "select() failed, errno %d\n", errno);
return;
}
// Let the library process any activity.
ares_process(channel, &readers, &writers);
// Let the provided callback process any activity on the extra FD.
for (ares_socket_t extrafd : extrafds) {
if (FD_ISSET(extrafd, &readers)) {
process_extra(extrafd);
}
}
}
}
// static
void LibraryTest::SetAllocFail(int nth) {
lock_.lock();
assert(nth > 0);
assert(nth <= (int)(8 * sizeof(fails_)));
fails_ |= (1LL << (nth - 1));
lock_.unlock();
}
// static
void LibraryTest::SetAllocSizeFail(size_t size) {
lock_.lock();
size_fails_[size]++;
lock_.unlock();
}
// static
void LibraryTest::ClearFails() {
lock_.lock();
fails_ = 0;
size_fails_.clear();
lock_.unlock();
}
// static
bool LibraryTest::ShouldAllocFail(size_t size) {
lock_.lock();
bool fail = (fails_ & 0x01);
fails_ >>= 1;
if (size_fails_[size] > 0) {
size_fails_[size]--;
fail = true;
}
lock_.unlock();
return fail;
}
// static
void* LibraryTest::amalloc(size_t size) {
if (ShouldAllocFail(size) || size == 0) {
if (verbose) std::cerr << "Failing malloc(" << size << ") request" << std::endl;
return nullptr;
} else {
return malloc(size);
}
}
// static
void* LibraryTest::arealloc(void *ptr, size_t size) {
if (ShouldAllocFail(size)) {
if (verbose) std::cerr << "Failing realloc(" << ptr << ", " << size << ") request" << std::endl;
return nullptr;
} else {
return realloc(ptr, size);
}
}
// static
void LibraryTest::afree(void *ptr) {
free(ptr);
}
std::set<ares_socket_t> NoExtraFDs() {
return std::set<ares_socket_t>();
}
void DefaultChannelTest::Process(unsigned int cancel_ms) {
ProcessWork(channel_, NoExtraFDs, nullptr, cancel_ms);
}
void FileChannelTest::Process(unsigned int cancel_ms) {
ProcessWork(channel_, NoExtraFDs, nullptr, cancel_ms);
}
void DefaultChannelModeTest::Process(unsigned int cancel_ms) {
ProcessWork(channel_, NoExtraFDs, nullptr, cancel_ms);
}
MockServer::MockServer(int family, unsigned short port)
: udpport_(port), tcpport_(port), qid_(-1) {
reply_ = nullptr;
// Create a TCP socket to receive data on.
tcp_data_ = NULL;
tcp_data_len_ = 0;
tcpfd_ = socket(family, SOCK_STREAM, 0);
EXPECT_NE(ARES_SOCKET_BAD, tcpfd_);
int optval = 1;
setsockopt(tcpfd_, SOL_SOCKET, SO_REUSEADDR,
BYTE_CAST &optval , sizeof(int));
// Send TCP data right away.
setsockopt(tcpfd_, IPPROTO_TCP, TCP_NODELAY,
BYTE_CAST &optval , sizeof(int));
#if defined(SO_NOSIGPIPE)
setsockopt(tcpfd_, SOL_SOCKET, SO_NOSIGPIPE, (void *)&optval, sizeof(optval));
#endif
/* Test system enable TCP FastOpen */
#if defined(TCP_FASTOPEN)
# ifdef __linux__
int qlen = 32;
setsockopt(tcpfd_, IPPROTO_TCP, TCP_FASTOPEN, &qlen, sizeof(qlen));
# else
int on = 1;
setsockopt(tcpfd_, IPPROTO_TCP, TCP_FASTOPEN, BYTE_CAST &on, sizeof(on));
# endif
#endif
// Create a UDP socket to receive data on.
udpfd_ = socket(family, SOCK_DGRAM, 0);
EXPECT_NE(ARES_SOCKET_BAD, udpfd_);
#if defined(SO_NOSIGPIPE)
setsockopt(udpfd_, SOL_SOCKET, SO_NOSIGPIPE, (void *)&optval, sizeof(optval));
#endif
// Bind the sockets to the given port.
if (family == AF_INET) {
struct sockaddr_in addr;
memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_addr.s_addr = htonl(INADDR_ANY);
addr.sin_port = htons(tcpport_);
int tcprc = bind(tcpfd_, (struct sockaddr*)&addr, sizeof(addr));
EXPECT_EQ(0, tcprc) << "Failed to bind AF_INET to TCP port " << tcpport_;
addr.sin_port = htons(udpport_);
int udprc = bind(udpfd_, (struct sockaddr*)&addr, sizeof(addr));
EXPECT_EQ(0, udprc) << "Failed to bind AF_INET to UDP port " << udpport_;
// retrieve system-assigned port
if (udpport_ == dynamic_port) {
ares_socklen_t len = sizeof(addr);
auto result = getsockname(udpfd_, (struct sockaddr*)&addr, &len);
EXPECT_EQ(0, result);
udpport_ = ntohs(addr.sin_port);
EXPECT_NE(dynamic_port, udpport_);
}
if (tcpport_ == dynamic_port) {
ares_socklen_t len = sizeof(addr);
auto result = getsockname(tcpfd_, (struct sockaddr*)&addr, &len);
EXPECT_EQ(0, result);
tcpport_ = ntohs(addr.sin_port);
EXPECT_NE(dynamic_port, tcpport_);
}
} else {
EXPECT_EQ(AF_INET6, family);
struct sockaddr_in6 addr;
memset(&addr, 0, sizeof(addr));
addr.sin6_family = AF_INET6;
memset(&addr.sin6_addr, 0, sizeof(addr.sin6_addr)); // in6addr_any
addr.sin6_port = htons(tcpport_);
int tcprc = bind(tcpfd_, (struct sockaddr*)&addr, sizeof(addr));
EXPECT_EQ(0, tcprc) << "Failed to bind AF_INET6 to TCP port " << tcpport_;
addr.sin6_port = htons(udpport_);
int udprc = bind(udpfd_, (struct sockaddr*)&addr, sizeof(addr));
EXPECT_EQ(0, udprc) << "Failed to bind AF_INET6 to UDP port " << udpport_;
// retrieve system-assigned port
if (udpport_ == dynamic_port) {
ares_socklen_t len = sizeof(addr);
auto result = getsockname(udpfd_, (struct sockaddr*)&addr, &len);
EXPECT_EQ(0, result);
udpport_ = ntohs(addr.sin6_port);
EXPECT_NE(dynamic_port, udpport_);
}
if (tcpport_ == dynamic_port) {
ares_socklen_t len = sizeof(addr);
auto result = getsockname(tcpfd_, (struct sockaddr*)&addr, &len);
EXPECT_EQ(0, result);
tcpport_ = ntohs(addr.sin6_port);
EXPECT_NE(dynamic_port, tcpport_);
}
}
if (verbose) std::cerr << "Configured "
<< (family == AF_INET ? "IPv4" : "IPv6")
<< " mock server with TCP socket " << tcpfd_
<< " on port " << tcpport_
<< " and UDP socket " << udpfd_
<< " on port " << udpport_ << std::endl;
// For TCP, also need to listen for connections.
EXPECT_EQ(0, listen(tcpfd_, 5)) << "Failed to listen for TCP connections";
}
MockServer::~MockServer() {
for (ares_socket_t fd : connfds_) {
sclose(fd);
}
sclose(tcpfd_);
sclose(udpfd_);
free(tcp_data_);
}
static unsigned short getaddrport(struct sockaddr_storage *addr)
{
if (addr->ss_family == AF_INET)
return ntohs(((struct sockaddr_in *)(void *)addr)->sin_port);
if (addr->ss_family == AF_INET6)
return ntohs(((struct sockaddr_in6 *)(void *)addr)->sin6_port);
/* TCP should use getpeername() to get the port, getting this from recvfrom
* won't work */
return 0;
}
void MockServer::ProcessPacket(ares_socket_t fd, struct sockaddr_storage *addr, ares_socklen_t addrlen,
byte *data, int len) {
// Assume the packet is a well-formed DNS request and extract the request
// details.
if (len < NS_HFIXEDSZ) {
std::cerr << "Packet too short (" << len << ")" << std::endl;
return;
}
int qid = DNS_HEADER_QID(data);
if (DNS_HEADER_QR(data) != 0) {
std::cerr << "Not a request" << std::endl;
return;
}
if (DNS_HEADER_OPCODE(data) != O_QUERY) {
std::cerr << "Not a query (opcode " << DNS_HEADER_OPCODE(data)
<< ")" << std::endl;
return;
}
if (DNS_HEADER_QDCOUNT(data) != 1) {
std::cerr << "Unexpected question count (" << DNS_HEADER_QDCOUNT(data)
<< ")" << std::endl;
return;
}
byte* question = data + NS_HFIXEDSZ;
int qlen = len - NS_HFIXEDSZ;
char *name = nullptr;
long enclen;
ares_expand_name(question, data, len, &name, &enclen);
if (!name) {
std::cerr << "Failed to retrieve name" << std::endl;
return;
}
if (enclen > qlen) {
std::cerr << "(error, encoded name len " << enclen << "bigger than remaining data " << qlen << " bytes)" << std::endl;
ares_free_string(name);
return;
}
qlen -= (int)enclen;
question += enclen;
if (qlen < 4) {
std::cerr << "Unexpected question size (" << qlen
<< " bytes after name)" << std::endl;
ares_free_string(name);
return;
}
if (DNS_QUESTION_CLASS(question) != C_IN) {
std::cerr << "Unexpected question class (" << DNS_QUESTION_CLASS(question)
<< ")" << std::endl;
ares_free_string(name);
return;
}
int rrtype = DNS_QUESTION_TYPE(question);
std::vector<byte> req(data, data + len);
std::string reqstr = PacketToString(req);
if (verbose) {
std::cerr << "received " << (fd == udpfd_ ? "UDP" : "TCP") << " request " << reqstr
<< " on port " << (fd == udpfd_ ? udpport_ : tcpport_)
<< ":" << getaddrport(addr) << std::endl;
std::cerr << "ProcessRequest(" << qid << ", '" << name
<< "', " << RRTypeToString(rrtype) << ")" << std::endl;
}
ProcessRequest(fd, addr, addrlen, req, reqstr, qid, name, rrtype);
ares_free_string(name);
}
void MockServer::ProcessFD(ares_socket_t fd) {
if (fd != tcpfd_ && fd != udpfd_ && connfds_.find(fd) == connfds_.end()) {
// Not one of our FDs.
return;
}
if (fd == tcpfd_) {
ares_socket_t connfd = accept(tcpfd_, NULL, NULL);
if (connfd == ARES_SOCKET_BAD) {
std::cerr << "Error accepting connection on fd " << fd << std::endl;
} else {
connfds_.insert(connfd);
}
return;
}
// Activity on a data-bearing file descriptor.
struct sockaddr_storage addr;
socklen_t addrlen = sizeof(addr);
memset(&addr, 0, sizeof(addr));
byte buffer[2048];
ares_ssize_t len = (ares_ssize_t)recvfrom(fd, BYTE_CAST buffer, sizeof(buffer), 0,
(struct sockaddr *)&addr, &addrlen);
if (fd != udpfd_) {
if (len <= 0) {
connfds_.erase(std::find(connfds_.begin(), connfds_.end(), fd));
sclose(fd);
free(tcp_data_);
tcp_data_ = NULL;
tcp_data_len_ = 0;
return;
}
tcp_data_ = (unsigned char *)realloc(tcp_data_, tcp_data_len_ + (size_t)len);
memcpy(tcp_data_ + tcp_data_len_, buffer, (size_t)len);
tcp_data_len_ += (size_t)len;
/* TCP might aggregate the various requests into a single packet, so we
* need to split */
while (tcp_data_len_ > 2) {
size_t tcplen = ((size_t)tcp_data_[0] << 8) + (size_t)tcp_data_[1];
if (tcp_data_len_ - 2 < tcplen)
break;
ProcessPacket(fd, &addr, addrlen, tcp_data_ + 2, (int)tcplen);
/* strip off processed data if connection not terminated */
if (tcp_data_ != NULL) {
memmove(tcp_data_, tcp_data_ + tcplen + 2, tcp_data_len_ - 2 - tcplen);
tcp_data_len_ -= 2 + tcplen;
}
}
} else {
/* UDP is always a single packet */
ProcessPacket(fd, &addr, addrlen, buffer, (int)len);
}
}
std::set<ares_socket_t> MockServer::fds() const {
std::set<ares_socket_t> result = connfds_;
result.insert(tcpfd_);
result.insert(udpfd_);
return result;
}
void MockServer::ProcessRequest(ares_socket_t fd, struct sockaddr_storage* addr,
ares_socklen_t addrlen, const std::vector<byte> &req,
const std::string &reqstr,
int qid, const char *name, int rrtype) {
/* DNS 0x20 will mix case, do case-insensitive matching of name in request */
char lower_name[256];
int flags = 0;
arestest_strtolower(lower_name, name, sizeof(lower_name));
// Before processing, let gMock know the request is happening.
OnRequest(lower_name, rrtype);
// If we are expecting a specific request then check it matches here.
if (expected_request_.length() > 0) {
ASSERT_EQ(expected_request_, reqstr);
}
if (reply_ != nullptr) {
ares_dns_record_t *dnsrec = NULL;
/* We will *attempt* to parse the request string. It may be malformed that
* will lead to a parse failure. If so, we just ignore it. We want to
* pass this parsed data structure to the reply generator in case it needs
* to extract metadata (such as a DNS client cookie) from the original
* request. If we can't parse it, oh well, we'll just pass NULL, most
* replies don't need anything from the request other than the name which
* is passed separately. */
ares_dns_parse(req.data(), req.size(), 0, &dnsrec);
exact_reply_ = reply_->data(name, dnsrec);
ares_dns_record_destroy(dnsrec);
}
if (exact_reply_.size() == 0) {
return;
}
// Make a local copy of the current pending reply.
std::vector<byte> reply = exact_reply_;
if (qid_ >= 0) {
// Use the explicitly specified query ID.
qid = qid_;
}
if (reply.size() >= 2) {
// Overwrite the query ID if space to do so.
reply[0] = (byte)((qid >> 8) & 0xff);
reply[1] = (byte)(qid & 0xff);
}
if (verbose) {
std::cerr << "sending reply " << PacketToString(reply)
<< " on port " << ((fd == udpfd_) ? udpport_ : tcpport_)
<< ":" << getaddrport(addr) << std::endl;
}
// Prefix with 2-byte length if TCP.
if (fd != udpfd_) {
int len = (int)reply.size();
std::vector<byte> vlen = {(byte)((len & 0xFF00) >> 8), (byte)(len & 0xFF)};
reply.insert(reply.begin(), vlen.begin(), vlen.end());
// Also, don't bother with the destination address.
addr = nullptr;
addrlen = 0;
}
#ifdef MSG_NOSIGNAL
flags |= MSG_NOSIGNAL;
#endif
ares_ssize_t rc = (ares_ssize_t)sendto(fd, BYTE_CAST reply.data(), (SEND_TYPE_ARG3)reply.size(), flags,
(struct sockaddr *)addr, addrlen);
if (rc < static_cast<ares_ssize_t>(reply.size())) {
std::cerr << "Failed to send full reply, rc=" << rc << std::endl;
}
}
// static
MockChannelOptsTest::NiceMockServers MockChannelOptsTest::BuildServers(int count, int family, unsigned short base_port) {
NiceMockServers servers;
assert(count > 0);
for (unsigned short ii = 0; ii < count; ii++) {
unsigned short port = base_port == dynamic_port ? dynamic_port : base_port + ii;
std::unique_ptr<NiceMockServer> server(new NiceMockServer(family, port));
servers.push_back(std::move(server));
}
return servers;
}
MockChannelOptsTest::MockChannelOptsTest(int count,
int family,
bool force_tcp,
struct ares_options* givenopts,
int optmask)
: servers_(BuildServers(count, family, mock_port)),
server_(*servers_[0].get()), channel_(nullptr) {
// Set up channel options.
struct ares_options opts;
if (givenopts) {
memcpy(&opts, givenopts, sizeof(opts));
} else {
memset(&opts, 0, sizeof(opts));
}
// Point the library at the first mock server by default (overridden below).
opts.udp_port = server_.udpport();
optmask |= ARES_OPT_UDP_PORT;
opts.tcp_port = server_.tcpport();
optmask |= ARES_OPT_TCP_PORT;
if (!(optmask & (ARES_OPT_TIMEOUTMS|ARES_OPT_TIMEOUT))) {
// Reduce timeouts significantly to shorten test times.
opts.timeout = 250;
optmask |= ARES_OPT_TIMEOUTMS;
}
// If not already overridden, set 3 retries.
if (!(optmask & ARES_OPT_TRIES)) {
opts.tries = 3;
optmask |= ARES_OPT_TRIES;
}
// If not already overridden, set search domains.
const char *domains[3] = {"first.com", "second.org", "third.gov"};
if (!(optmask & ARES_OPT_DOMAINS)) {
opts.ndomains = 3;
opts.domains = (char**)domains;
optmask |= ARES_OPT_DOMAINS;
}
if (force_tcp) {
opts.flags |= ARES_FLAG_USEVC;
optmask |= ARES_OPT_FLAGS;
}
/* Tests expect ndots=1 in general, the system config may not default to this
* so we don't want to inherit that. */
if (!(optmask & ARES_OPT_NDOTS)) {
opts.ndots = 1;
optmask |= ARES_OPT_NDOTS;
}
/* Disable the query cache for tests unless explicitly enabled. As of
* c-ares 1.31.0, the query cache is enabled by default so we have to set
* the option and set the TTL to 0 to effectively disable it. */
if (!(optmask & ARES_OPT_QUERY_CACHE)) {
opts.qcache_max_ttl = 0;
optmask |= ARES_OPT_QUERY_CACHE;
}
/* Enable DNS0x20 by default. Need to also turn on default flag of EDNS */
if (!(optmask & ARES_OPT_FLAGS)) {
optmask |= ARES_OPT_FLAGS;
opts.flags = ARES_FLAG_DNS0x20|ARES_FLAG_EDNS;
}
EXPECT_EQ(ARES_SUCCESS, ares_init_options(&channel_, &opts, optmask));
EXPECT_NE(nullptr, channel_);
// Set up servers after construction so we can set individual ports
struct ares_addr_port_node* prev = nullptr;
struct ares_addr_port_node* first = nullptr;
for (const auto& server : servers_) {
struct ares_addr_port_node* node = (struct ares_addr_port_node*)malloc(sizeof(*node));
if (prev) {
prev->next = node;
} else {
first = node;
}
node->next = nullptr;
node->family = family;
node->udp_port = server->udpport();
node->tcp_port = server->tcpport();
if (family == AF_INET) {
node->addr.addr4.s_addr = htonl(0x7F000001);
} else {
memset(&node->addr.addr6, 0, sizeof(node->addr.addr6));
node->addr.addr6._S6_un._S6_u8[15] = 1;
}
prev = node;
}
EXPECT_EQ(ARES_SUCCESS, ares_set_servers_ports(channel_, first));
while (first) {
prev = first;
first = first->next;
free(prev);
}
if (verbose) {
std::cerr << "Configured library with servers:";
std::cerr << GetNameServers(channel_);
std::cerr << std::endl;
}
}
MockChannelOptsTest::~MockChannelOptsTest() {
if (channel_) {
ares_destroy(channel_);
}
channel_ = nullptr;
}
std::set<ares_socket_t> MockChannelOptsTest::fds() const {
std::set<ares_socket_t> fds;
for (const auto& server : servers_) {
std::set<ares_socket_t> serverfds = server->fds();
fds.insert(serverfds.begin(), serverfds.end());
}
return fds;
}
void MockChannelOptsTest::ProcessFD(ares_socket_t fd) {
for (auto& server : servers_) {
server->ProcessFD(fd);
}
}
void MockChannelOptsTest::Process(unsigned int cancel_ms) {
using namespace std::placeholders;
ProcessWork(channel_,
std::bind(&MockChannelOptsTest::fds, this),
std::bind(&MockChannelOptsTest::ProcessFD, this, _1),
cancel_ms);
}
void MockEventThreadOptsTest::Process(unsigned int cancel_ms) {
std::set<ares_socket_t> fds;
auto tv_begin = std::chrono::high_resolution_clock::now();
auto tv_cancel = tv_begin;
if (cancel_ms) {
if (verbose) std::cerr << "ares_cancel will be called after " << cancel_ms << "ms" << std::endl;
tv_cancel += std::chrono::milliseconds(cancel_ms);
}
while (ares_queue_active_queries(channel_)) {
//if (verbose) std::cerr << "pending queries: " << ares_queue_active_queries(channel_) << std::endl;
int nfds = 0;
fd_set readers;
struct timeval tv;
/* c-ares is using its own event thread, so we only need to monitor the
* extrafds passed in */
FD_ZERO(&readers);
fds = MockEventThreadOptsTest::fds();
for (ares_socket_t fd : fds) {
FD_SET(fd, &readers);
if (fd >= (ares_socket_t)nfds) {
nfds = (int)fd + 1;
}
}
/* We just always wait 20ms then recheck if we're done. Not doing any
* complex signaling. */
tv.tv_sec = 0;
tv.tv_usec = 20000;
if (cancel_ms) {
auto tv_now = std::chrono::high_resolution_clock::now();
auto remaining_ms = std::chrono::duration_cast<std::chrono::milliseconds>(tv_cancel - tv_now).count();
if (remaining_ms <= 0) {
if (verbose) std::cerr << "Issuing ares_cancel()" << std::endl;
ares_cancel(channel_);
cancel_ms = 0; /* Disable issuing cancel again */
} else {
tv.tv_sec = remaining_ms / 1000;
tv.tv_usec = (int)(remaining_ms % 1000);
}
}
if (select(nfds, &readers, nullptr, nullptr, &tv) < 0) {
fprintf(stderr, "select() failed, errno %d\n", errno);
return;
}
// Let the provided callback process any activity on the extra FD.
for (ares_socket_t fd : fds) {
if (FD_ISSET(fd, &readers)) {
ProcessFD(fd);
}
}
}
//if (verbose) std::cerr << "pending queries at process end: " << ares_queue_active_queries(channel_) << std::endl;
}
std::ostream& operator<<(std::ostream& os, const HostResult& result) {
os << '{';
if (result.done_) {
os << StatusToString(result.status_);
if (result.host_.addrtype_ != -1) {
os << " " << result.host_;
} else {
os << ", (no hostent)";
}
} else {
os << "(incomplete)";
}
os << '}';
return os;
}
HostEnt::HostEnt(const struct hostent *hostent) : addrtype_(-1) {
if (!hostent)
return;
if (hostent->h_name) {
// DNS 0x20 may mix case, output as all lower for checks as the mixed case
// is really more of an internal thing
char lowername[256];
arestest_strtolower(lowername, hostent->h_name, sizeof(lowername));
name_ = lowername;
}
if (hostent->h_aliases) {
char** palias = hostent->h_aliases;
while (*palias != nullptr) {
aliases_.push_back(*palias);
palias++;
}
}
addrtype_ = hostent->h_addrtype;
if (hostent->h_addr_list) {
char** paddr = hostent->h_addr_list;
while (*paddr != nullptr) {
std::string addr = AddressToString(*paddr, hostent->h_length);
addrs_.push_back(addr);
paddr++;
}
}
}
std::ostream& operator<<(std::ostream& os, const HostEnt& host) {
os << "{'";
if (host.name_.length() > 0) {
os << host.name_;
}
os << "' aliases=[";
for (size_t ii = 0; ii < host.aliases_.size(); ii++) {
if (ii > 0) os << ", ";
os << host.aliases_[ii];
}
os << "] ";
os << "addrs=[";
for (size_t ii = 0; ii < host.addrs_.size(); ii++) {
if (ii > 0) os << ", ";
os << host.addrs_[ii];
}
os << "]";
os << '}';
return os;
}
void HostCallback(void *data, int status, int timeouts,
struct hostent *hostent) {
EXPECT_NE(nullptr, data);
if (data == nullptr)
return;
HostResult* result = reinterpret_cast<HostResult*>(data);
result->done_ = true;
result->status_ = status;
result->timeouts_ = timeouts;
if (hostent)
result->host_ = HostEnt(hostent);
if (verbose) std::cerr << "HostCallback(" << *result << ")" << std::endl;
}
std::ostream& operator<<(std::ostream& os, const AresDnsRecord& dnsrec) {
os << "{'";
/* XXX: Todo */
os << '}';
return os;
}
std::ostream& operator<<(std::ostream& os, const QueryResult& result) {
os << '{';
if (result.done_) {
os << StatusToString(result.status_);
if (result.dnsrec_.dnsrec_ != nullptr) {
os << " " << result.dnsrec_;
} else {
os << ", (no dnsrec)";
}
} else {
os << "(incomplete)";
}
os << '}';
return os;
}
void QueryCallback(void *data, ares_status_t status, size_t timeouts,
const ares_dns_record_t *dnsrec) {
EXPECT_NE(nullptr, data);
if (data == nullptr)
return;
QueryResult* result = reinterpret_cast<QueryResult*>(data);
result->done_ = true;
result->status_ = status;
result->timeouts_ = timeouts;
if (dnsrec)
result->dnsrec_.SetDnsRecord(dnsrec);
if (verbose) std::cerr << "QueryCallback(" << *result << ")" << std::endl;
}
std::ostream& operator<<(std::ostream& os, const AddrInfoResult& result) {
os << '{';
if (result.done_ && result.ai_) {
os << StatusToString(result.status_) << " " << result.ai_;
} else {
os << "(incomplete)";
}
os << '}';
return os;
}
std::ostream& operator<<(std::ostream& os, const AddrInfo& ai) {
os << '{';
if (ai == nullptr) {
os << "nullptr}";
return os;
}
struct ares_addrinfo_cname *next_cname = ai->cnames;
while(next_cname) {
if(next_cname->alias) {
os << next_cname->alias << "->";
}
if(next_cname->name) {
os << next_cname->name;
}
next_cname = next_cname->next;
if (next_cname != NULL)
os << ", ";
else
os << " ";
}
struct ares_addrinfo_node *next = ai->nodes;
while(next) {
//if(next->ai_canonname) {
//os << "'" << next->ai_canonname << "' ";
//}
unsigned short port = 0;
os << "addr=[";
if(next->ai_family == AF_INET) {
sockaddr_in* sin = (sockaddr_in *)((void *)next->ai_addr);
port = ntohs(sin->sin_port);
os << AddressToString(&sin->sin_addr, 4);
}
else if (next->ai_family == AF_INET6) {
sockaddr_in6* sin = (sockaddr_in6*)((void *)next->ai_addr);
port = ntohs(sin->sin6_port);
os << "[" << AddressToString(&sin->sin6_addr, 16) << "]";
}
else
os << "unknown family";
if(port) {
os << ":" << port;
}
os << "]";
next = next->ai_next;
if (next != NULL)
os << ", ";
}
os << '}';
return os;
}
void AddrInfoCallback(void *data, int status, int timeouts,
struct ares_addrinfo *ai) {
EXPECT_NE(nullptr, data);
AddrInfoResult* result = reinterpret_cast<AddrInfoResult*>(data);
result->done_ = true;
result->status_ = status;
result->timeouts_= timeouts;
if (ai)
result->ai_ = AddrInfo(ai);
if (verbose) std::cerr << "AddrInfoCallback(" << *result << ")" << std::endl;
}
std::ostream& operator<<(std::ostream& os, const SearchResult& result) {
os << '{';
if (result.done_) {
os << StatusToString(result.status_) << " " << PacketToString(result.data_);
} else {
os << "(incomplete)";
}
os << '}';
return os;
}
void SearchCallback(void *data, int status, int timeouts,
unsigned char *abuf, int alen) {
EXPECT_NE(nullptr, data);
SearchResult* result = reinterpret_cast<SearchResult*>(data);
result->done_ = true;
result->status_ = status;
result->timeouts_ = timeouts;
result->data_.assign(abuf, abuf + alen);
if (verbose) std::cerr << "SearchCallback(" << *result << ")" << std::endl;
}
void SearchCallbackDnsRec(void *data, ares_status_t status, size_t timeouts,
const ares_dns_record_t *dnsrec) {
EXPECT_NE(nullptr, data);
SearchResult* result = reinterpret_cast<SearchResult*>(data);
unsigned char *abuf = NULL;
size_t alen = 0;
result->done_ = true;
result->status_ = (int)status;
result->timeouts_ = (int)timeouts;
if (dnsrec != NULL) {
ares_dns_write(dnsrec, &abuf, &alen);
}
result->data_.assign(abuf, abuf + alen);
ares_free_string(abuf);
if (verbose) std::cerr << "SearchCallbackDnsRec(" << *result << ")" << std::endl;
}
std::ostream& operator<<(std::ostream& os, const NameInfoResult& result) {
os << '{';
if (result.done_) {
os << StatusToString(result.status_) << " " << result.node_ << " " << result.service_;
} else {
os << "(incomplete)";
}
os << '}';
return os;
}
void NameInfoCallback(void *data, int status, int timeouts,
char *node, char *service) {
EXPECT_NE(nullptr, data);
NameInfoResult* result = reinterpret_cast<NameInfoResult*>(data);
result->done_ = true;
result->status_ = status;
result->timeouts_ = timeouts;
result->node_ = std::string(node ? node : "");
result->service_ = std::string(service ? service : "");
if (verbose) std::cerr << "NameInfoCallback(" << *result << ")" << std::endl;
}
std::string GetNameServers(ares_channel_t *channel) {
char *csv = ares_get_servers_csv(channel);
EXPECT_NE((char *)NULL, csv);
std::string servers(csv);
ares_free_string(csv);
return servers;
}
TransientDir::TransientDir(const std::string& dirname) : dirname_(dirname) {
if (mkdir_(dirname_.c_str(), 0755) != 0) {
std::cerr << "Failed to create subdirectory '" << dirname_ << "'" << std::endl;
}
}
TransientDir::~TransientDir() {
rmdir(dirname_.c_str());
}
TransientFile::TransientFile(const std::string& filename,
const std::string& contents)
: filename_(filename) {
FILE *f = fopen(filename.c_str(), "w");
if (f == nullptr) {
std::cerr << "Error: failed to create '" << filename << "'" << std::endl;
return;
}
size_t rc = (size_t)fwrite(contents.data(), 1, contents.size(), f);
if (rc != contents.size()) {
std::cerr << "Error: failed to write contents of '" << filename << "'" << std::endl;
}
fclose(f);
}
TransientFile::~TransientFile() {
unlink(filename_.c_str());
}
std::string TempNam(const char *dir, const char *prefix) {
char *p = tempnam(dir, prefix);
std::string result(p);
free(p);
return result;
}
TempFile::TempFile(const std::string& contents)
: TransientFile(TempNam(nullptr, "ares"), contents) {
}
VirtualizeIO::VirtualizeIO(ares_channel_t *c)
: channel_(c)
{
ares_set_socket_functions(channel_, &default_functions, 0);
}
VirtualizeIO::~VirtualizeIO() {
ares_set_socket_functions(channel_, 0, 0);
}
} // namespace test
} // namespace ares