/*
* Copyright (C) 2017 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef NETDUTILS_SYSCALLS_H
#define NETDUTILS_SYSCALLS_H
#include <memory>
#include <poll.h>
#include <unistd.h>
#include <sys/eventfd.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/uio.h>
#include "netdutils/Slice.h"
#include "netdutils/Socket.h"
#include "netdutils/Status.h"
#include "netdutils/StatusOr.h"
#include "netdutils/UniqueFd.h"
#include "netdutils/UniqueFile.h"
namespace android {
namespace netdutils {
class Syscalls {
public:
virtual ~Syscalls() = default;
virtual StatusOr<UniqueFd> open(const std::string& pathname, int flags,
mode_t mode = 0) const = 0;
virtual StatusOr<UniqueFd> socket(int domain, int type, int protocol) const = 0;
virtual Status getsockname(Fd sock, sockaddr* addr, socklen_t* addrlen) const = 0;
virtual Status getsockopt(Fd sock, int level, int optname, void *optval,
socklen_t *optlen) const = 0;
virtual Status setsockopt(Fd sock, int level, int optname, const void* optval,
socklen_t optlen) const = 0;
virtual Status bind(Fd sock, const sockaddr* addr, socklen_t addrlen) const = 0;
virtual Status connect(Fd sock, const sockaddr* addr, socklen_t addrlen) const = 0;
virtual StatusOr<UniqueFd> eventfd(unsigned int initval, int flags) const = 0;
virtual StatusOr<int> ppoll(pollfd* fds, nfds_t nfds, double timeout) const = 0;
virtual StatusOr<size_t> writev(Fd fd, const std::vector<iovec>& iov) const = 0;
virtual StatusOr<size_t> write(Fd fd, const Slice buf) const = 0;
virtual StatusOr<Slice> read(Fd fd, const Slice buf) const = 0;
virtual StatusOr<size_t> sendto(Fd sock, const Slice buf, int flags, const sockaddr* dst,
socklen_t dstlen) const = 0;
virtual StatusOr<Slice> recvfrom(Fd sock, const Slice dst, int flags, sockaddr* src,
socklen_t* srclen) const = 0;
virtual Status shutdown(Fd fd, int how) const = 0;
virtual Status close(Fd fd) const = 0;
virtual StatusOr<UniqueFile> fopen(const std::string& path, const std::string& mode) const = 0;
virtual StatusOr<int> vfprintf(FILE* file, const char* format, va_list ap) const = 0;
virtual StatusOr<int> vfscanf(FILE* file, const char* format, va_list ap) const = 0;
virtual Status fclose(FILE* file) const = 0;
virtual StatusOr<pid_t> fork() const = 0;
// va_args helpers
// va_start doesn't work when the preceding argument is a reference
// type so we're forced to use const char*.
StatusOr<int> fprintf(FILE* file, const char* format, ...) const {
va_list ap;
va_start(ap, format);
auto result = vfprintf(file, format, ap);
va_end(ap);
return result;
}
// va_start doesn't work when the preceding argument is a reference
// type so we're forced to use const char*.
StatusOr<int> fscanf(FILE* file, const char* format, ...) const {
va_list ap;
va_start(ap, format);
auto result = vfscanf(file, format, ap);
va_end(ap);
return result;
}
// Templated helpers that forward directly to methods declared above
template <typename SockaddrT>
StatusOr<SockaddrT> getsockname(Fd sock) const {
SockaddrT addr = {};
socklen_t addrlen = sizeof(addr);
RETURN_IF_NOT_OK(getsockname(sock, asSockaddrPtr(&addr), &addrlen));
return addr;
}
template <typename SockoptT>
Status getsockopt(Fd sock, int level, int optname, void* optval, socklen_t* optlen) const {
return getsockopt(sock, level, optname, optval, optlen);
}
template <typename SockoptT>
Status setsockopt(Fd sock, int level, int optname, const SockoptT& opt) const {
return setsockopt(sock, level, optname, &opt, sizeof(opt));
}
template <typename SockaddrT>
Status bind(Fd sock, const SockaddrT& addr) const {
return bind(sock, asSockaddrPtr(&addr), sizeof(addr));
}
template <typename SockaddrT>
Status connect(Fd sock, const SockaddrT& addr) const {
return connect(sock, asSockaddrPtr(&addr), sizeof(addr));
}
template <size_t size>
StatusOr<std::array<uint16_t, size>> ppoll(const std::array<Fd, size>& fds, uint16_t events,
double timeout) const {
std::array<pollfd, size> tmp;
for (size_t i = 0; i < size; ++i) {
tmp[i].fd = fds[i].get();
tmp[i].events = events;
tmp[i].revents = 0;
}
RETURN_IF_NOT_OK(ppoll(tmp.data(), tmp.size(), timeout).status());
std::array<uint16_t, size> out;
for (size_t i = 0; i < size; ++i) {
out[i] = tmp[i].revents;
}
return out;
}
template <typename SockaddrT>
StatusOr<size_t> sendto(Fd sock, const Slice buf, int flags, const SockaddrT& dst) const {
return sendto(sock, buf, flags, asSockaddrPtr(&dst), sizeof(dst));
}
// Ignore src sockaddr
StatusOr<Slice> recvfrom(Fd sock, const Slice dst, int flags) const {
return recvfrom(sock, dst, flags, nullptr, nullptr);
}
template <typename SockaddrT>
StatusOr<std::pair<Slice, SockaddrT>> recvfrom(Fd sock, const Slice dst, int flags) const {
SockaddrT addr = {};
socklen_t addrlen = sizeof(addr);
ASSIGN_OR_RETURN(auto used, recvfrom(sock, dst, flags, asSockaddrPtr(&addr), &addrlen));
return std::make_pair(used, addr);
}
};
// Specialized singleton that supports zero initialization and runtime
// override of contained pointer.
class SyscallsHolder {
public:
~SyscallsHolder();
// Return a pointer to an unowned instance of Syscalls.
Syscalls& get();
// Testing only: set the value returned by getSyscalls. Return the old value.
// Callers are responsible for restoring the previous value returned
// by getSyscalls to avoid leaks.
Syscalls& swap(Syscalls& syscalls);
private:
std::atomic<Syscalls*> mSyscalls{nullptr};
};
// Syscalls instance used throughout netdutils
extern SyscallsHolder sSyscalls;
} // namespace netdutils
} // namespace android
#endif /* NETDUTILS_SYSCALLS_H */